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diff --git a/doc/arm/Bv9ARM.ch06.html b/doc/arm/Bv9ARM.ch06.html new file mode 100644 index 0000000..d829a17 --- /dev/null +++ b/doc/arm/Bv9ARM.ch06.html @@ -0,0 +1,7114 @@ +<!-- + - Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC") + - Copyright (C) 2000-2003 Internet Software Consortium. + - + - Permission to use, copy, modify, and distribute this software for any + - purpose with or without fee is hereby granted, provided that the above + - copyright notice and this permission notice appear in all copies. + - + - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + - PERFORMANCE OF THIS SOFTWARE. +--> +<!-- $Id: Bv9ARM.ch06.html,v 1.82.18.73 2007/10/31 01:35:58 marka Exp $ --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>Chapter 6. BIND 9 Configuration Reference</title> +<meta name="generator" content="DocBook XSL Stylesheets V1.71.1"> +<link rel="start" href="Bv9ARM.html" title="BIND 9 Administrator Reference Manual"> +<link rel="up" href="Bv9ARM.html" title="BIND 9 Administrator Reference Manual"> +<link rel="prev" href="Bv9ARM.ch05.html" title="Chapter 5. The BIND 9 Lightweight Resolver"> +<link rel="next" href="Bv9ARM.ch07.html" title="Chapter 7. BIND 9 Security Considerations"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<div class="navheader"> +<table width="100%" summary="Navigation header"> +<tr><th colspan="3" align="center">Chapter 6. <acronym class="acronym">BIND</acronym> 9 Configuration Reference</th></tr> +<tr> +<td width="20%" align="left"> +<a accesskey="p" href="Bv9ARM.ch05.html">Prev</a> </td> +<th width="60%" align="center"> </th> +<td width="20%" align="right"> <a accesskey="n" href="Bv9ARM.ch07.html">Next</a> +</td> +</tr> +</table> +<hr> +</div> +<div class="chapter" lang="en"> +<div class="titlepage"><div><div><h2 class="title"> +<a name="Bv9ARM.ch06"></a>Chapter 6. <acronym class="acronym">BIND</acronym> 9 Configuration Reference</h2></div></div></div> +<div class="toc"> +<p><b>Table of Contents</b></p> +<dl> +<dt><span class="sect1"><a href="Bv9ARM.ch06.html#configuration_file_elements">Configuration File Elements</a></span></dt> +<dd><dl> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#address_match_lists">Address Match Lists</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2573480">Comment Syntax</a></span></dt> +</dl></dd> +<dt><span class="sect1"><a href="Bv9ARM.ch06.html#Configuration_File_Grammar">Configuration File Grammar</a></span></dt> +<dd><dl> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2574092"><span><strong class="command">acl</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#acl"><span><strong class="command">acl</strong></span> Statement Definition and + Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2574282"><span><strong class="command">controls</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#controls_statement_definition_and_usage"><span><strong class="command">controls</strong></span> Statement Definition and + Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2574711"><span><strong class="command">include</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2574726"><span><strong class="command">include</strong></span> Statement Definition and + Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2574749"><span><strong class="command">key</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2574771"><span><strong class="command">key</strong></span> Statement Definition and Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2574930"><span><strong class="command">logging</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2575056"><span><strong class="command">logging</strong></span> Statement Definition and + Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2576406"><span><strong class="command">lwres</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2576480"><span><strong class="command">lwres</strong></span> Statement Definition and Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2576544"><span><strong class="command">masters</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2576587"><span><strong class="command">masters</strong></span> Statement Definition and + Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2576602"><span><strong class="command">options</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#options"><span><strong class="command">options</strong></span> Statement Definition and + Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#server_statement_grammar"><span><strong class="command">server</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#server_statement_definition_and_usage"><span><strong class="command">server</strong></span> Statement Definition and + Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2585361"><span><strong class="command">trusted-keys</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2585410"><span><strong class="command">trusted-keys</strong></span> Statement Definition + and Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#view_statement_grammar"><span><strong class="command">view</strong></span> Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2585490"><span><strong class="command">view</strong></span> Statement Definition and Usage</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#zone_statement_grammar"><span><strong class="command">zone</strong></span> + Statement Grammar</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2586798"><span><strong class="command">zone</strong></span> Statement Definition and Usage</a></span></dt> +</dl></dd> +<dt><span class="sect1"><a href="Bv9ARM.ch06.html#id2589080">Zone File</a></span></dt> +<dd><dl> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#types_of_resource_records_and_when_to_use_them">Types of Resource Records and When to Use Them</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2591101">Discussion of MX Records</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#Setting_TTLs">Setting TTLs</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2591653">Inverse Mapping in IPv4</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2591848">Other Zone File Directives</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#id2592173"><acronym class="acronym">BIND</acronym> Master File Extension: the <span><strong class="command">$GENERATE</strong></span> Directive</a></span></dt> +<dt><span class="sect2"><a href="Bv9ARM.ch06.html#zonefile_format">Additional File Formats</a></span></dt> +</dl></dd> +</dl> +</div> +<p> + <acronym class="acronym">BIND</acronym> 9 configuration is broadly similar + to <acronym class="acronym">BIND</acronym> 8; however, there are a few new + areas + of configuration, such as views. <acronym class="acronym">BIND</acronym> + 8 configuration files should work with few alterations in <acronym class="acronym">BIND</acronym> + 9, although more complex configurations should be reviewed to check + if they can be more efficiently implemented using the new features + found in <acronym class="acronym">BIND</acronym> 9. + </p> +<p> + <acronym class="acronym">BIND</acronym> 4 configuration files can be + converted to the new format + using the shell script + <code class="filename">contrib/named-bootconf/named-bootconf.sh</code>. + </p> +<div class="sect1" lang="en"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="configuration_file_elements"></a>Configuration File Elements</h2></div></div></div> +<p> + Following is a list of elements used throughout the <acronym class="acronym">BIND</acronym> configuration + file documentation: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + <code class="varname">acl_name</code> + </p> + </td> +<td> + <p> + The name of an <code class="varname">address_match_list</code> as + defined by the <span><strong class="command">acl</strong></span> statement. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">address_match_list</code> + </p> + </td> +<td> + <p> + A list of one or more + <code class="varname">ip_addr</code>, + <code class="varname">ip_prefix</code>, <code class="varname">key_id</code>, + or <code class="varname">acl_name</code> elements, see + <a href="Bv9ARM.ch06.html#address_match_lists" title="Address Match Lists">the section called “Address Match Lists”</a>. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">masters_list</code> + </p> + </td> +<td> + <p> + A named list of one or more <code class="varname">ip_addr</code> + with optional <code class="varname">key_id</code> and/or + <code class="varname">ip_port</code>. + A <code class="varname">masters_list</code> may include other + <code class="varname">masters_lists</code>. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">domain_name</code> + </p> + </td> +<td> + <p> + A quoted string which will be used as + a DNS name, for example "<code class="literal">my.test.domain</code>". + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">dotted_decimal</code> + </p> + </td> +<td> + <p> + One to four integers valued 0 through + 255 separated by dots (`.'), such as <span><strong class="command">123</strong></span>, + <span><strong class="command">45.67</strong></span> or <span><strong class="command">89.123.45.67</strong></span>. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">ip4_addr</code> + </p> + </td> +<td> + <p> + An IPv4 address with exactly four elements + in <code class="varname">dotted_decimal</code> notation. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">ip6_addr</code> + </p> + </td> +<td> + <p> + An IPv6 address, such as <span><strong class="command">2001:db8::1234</strong></span>. + IPv6 scoped addresses that have ambiguity on their scope + zones must be + disambiguated by an appropriate zone ID with the percent + character + (`%') as delimiter. + It is strongly recommended to use string zone names rather + than + numeric identifiers, in order to be robust against system + configuration changes. + However, since there is no standard mapping for such names + and + identifier values, currently only interface names as link + identifiers + are supported, assuming one-to-one mapping between + interfaces and links. + For example, a link-local address <span><strong class="command">fe80::1</strong></span> on the + link attached to the interface <span><strong class="command">ne0</strong></span> + can be specified as <span><strong class="command">fe80::1%ne0</strong></span>. + Note that on most systems link-local addresses always have + the + ambiguity, and need to be disambiguated. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">ip_addr</code> + </p> + </td> +<td> + <p> + An <code class="varname">ip4_addr</code> or <code class="varname">ip6_addr</code>. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">ip_port</code> + </p> + </td> +<td> + <p> + An IP port <code class="varname">number</code>. + The <code class="varname">number</code> is limited to 0 + through 65535, with values + below 1024 typically restricted to use by processes running + as root. + In some cases, an asterisk (`*') character can be used as a + placeholder to + select a random high-numbered port. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">ip_prefix</code> + </p> + </td> +<td> + <p> + An IP network specified as an <code class="varname">ip_addr</code>, + followed by a slash (`/') and then the number of bits in the + netmask. + Trailing zeros in a <code class="varname">ip_addr</code> + may omitted. + For example, <span><strong class="command">127/8</strong></span> is the + network <span><strong class="command">127.0.0.0</strong></span> with + netmask <span><strong class="command">255.0.0.0</strong></span> and <span><strong class="command">1.2.3.0/28</strong></span> is + network <span><strong class="command">1.2.3.0</strong></span> with netmask <span><strong class="command">255.255.255.240</strong></span>. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">key_id</code> + </p> + </td> +<td> + <p> + A <code class="varname">domain_name</code> representing + the name of a shared key, to be used for transaction + security. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">key_list</code> + </p> + </td> +<td> + <p> + A list of one or more + <code class="varname">key_id</code>s, + separated by semicolons and ending with a semicolon. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">number</code> + </p> + </td> +<td> + <p> + A non-negative 32-bit integer + (i.e., a number between 0 and 4294967295, inclusive). + Its acceptable value might further + be limited by the context in which it is used. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">path_name</code> + </p> + </td> +<td> + <p> + A quoted string which will be used as + a pathname, such as <code class="filename">zones/master/my.test.domain</code>. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">size_spec</code> + </p> + </td> +<td> + <p> + A number, the word <strong class="userinput"><code>unlimited</code></strong>, + or the word <strong class="userinput"><code>default</code></strong>. + </p> + <p> + An <code class="varname">unlimited</code> <code class="varname">size_spec</code> requests unlimited + use, or the maximum available amount. A <code class="varname">default size_spec</code> uses + the limit that was in force when the server was started. + </p> + <p> + A <code class="varname">number</code> can optionally be + followed by a scaling factor: + <strong class="userinput"><code>K</code></strong> or <strong class="userinput"><code>k</code></strong> + for kilobytes, + <strong class="userinput"><code>M</code></strong> or <strong class="userinput"><code>m</code></strong> + for megabytes, and + <strong class="userinput"><code>G</code></strong> or <strong class="userinput"><code>g</code></strong> for gigabytes, + which scale by 1024, 1024*1024, and 1024*1024*1024 + respectively. + </p> + <p> + The value must be representable as a 64-bit unsigned integer + (0 to 18446744073709551615, inclusive). + Using <code class="varname">unlimited</code> is the best + way + to safely set a really large number. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">yes_or_no</code> + </p> + </td> +<td> + <p> + Either <strong class="userinput"><code>yes</code></strong> or <strong class="userinput"><code>no</code></strong>. + The words <strong class="userinput"><code>true</code></strong> and <strong class="userinput"><code>false</code></strong> are + also accepted, as are the numbers <strong class="userinput"><code>1</code></strong> + and <strong class="userinput"><code>0</code></strong>. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">dialup_option</code> + </p> + </td> +<td> + <p> + One of <strong class="userinput"><code>yes</code></strong>, + <strong class="userinput"><code>no</code></strong>, <strong class="userinput"><code>notify</code></strong>, + <strong class="userinput"><code>notify-passive</code></strong>, <strong class="userinput"><code>refresh</code></strong> or + <strong class="userinput"><code>passive</code></strong>. + When used in a zone, <strong class="userinput"><code>notify-passive</code></strong>, + <strong class="userinput"><code>refresh</code></strong>, and <strong class="userinput"><code>passive</code></strong> + are restricted to slave and stub zones. + </p> + </td> +</tr> +</tbody> +</table></div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="address_match_lists"></a>Address Match Lists</h3></div></div></div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2573277"></a>Syntax</h4></div></div></div> +<pre class="programlisting"><code class="varname">address_match_list</code> = address_match_list_element ; + [<span class="optional"> address_match_list_element; ... </span>] +<code class="varname">address_match_list_element</code> = [<span class="optional"> ! </span>] (ip_address [<span class="optional">/length</span>] | + key key_id | acl_name | { address_match_list } ) +</pre> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2573305"></a>Definition and Usage</h4></div></div></div> +<p> + Address match lists are primarily used to determine access + control for various server operations. They are also used in + the <span><strong class="command">listen-on</strong></span> and <span><strong class="command">sortlist</strong></span> + statements. The elements + which constitute an address match list can be any of the + following: + </p> +<div class="itemizedlist"><ul type="disc"> +<li>an IP address (IPv4 or IPv6)</li> +<li>an IP prefix (in `/' notation)</li> +<li> + a key ID, as defined by the <span><strong class="command">key</strong></span> + statement + </li> +<li>the name of an address match list defined with + the <span><strong class="command">acl</strong></span> statement + </li> +<li>a nested address match list enclosed in braces</li> +</ul></div> +<p> + Elements can be negated with a leading exclamation mark (`!'), + and the match list names "any", "none", "localhost", and + "localnets" + are predefined. More information on those names can be found in + the description of the acl statement. + </p> +<p> + The addition of the key clause made the name of this syntactic + element something of a misnomer, since security keys can be used + to validate access without regard to a host or network address. + Nonetheless, + the term "address match list" is still used throughout the + documentation. + </p> +<p> + When a given IP address or prefix is compared to an address + match list, the list is traversed in order until an element + matches. + The interpretation of a match depends on whether the list is being + used + for access control, defining listen-on ports, or in a sortlist, + and whether the element was negated. + </p> +<p> + When used as an access control list, a non-negated match + allows access and a negated match denies access. If + there is no match, access is denied. The clauses + <span><strong class="command">allow-notify</strong></span>, + <span><strong class="command">allow-query</strong></span>, + <span><strong class="command">allow-query-cache</strong></span>, + <span><strong class="command">allow-transfer</strong></span>, + <span><strong class="command">allow-update</strong></span>, + <span><strong class="command">allow-update-forwarding</strong></span>, and + <span><strong class="command">blackhole</strong></span> all use address match + lists. Similarly, the listen-on option will cause the + server to not accept queries on any of the machine's + addresses which do not match the list. + </p> +<p> + Because of the first-match aspect of the algorithm, an element + that defines a subset of another element in the list should come + before the broader element, regardless of whether either is + negated. For + example, in + <span><strong class="command">1.2.3/24; ! 1.2.3.13;</strong></span> the 1.2.3.13 + element is + completely useless because the algorithm will match any lookup for + 1.2.3.13 to the 1.2.3/24 element. + Using <span><strong class="command">! 1.2.3.13; 1.2.3/24</strong></span> fixes + that problem by having 1.2.3.13 blocked by the negation but all + other 1.2.3.* hosts fall through. + </p> +</div> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2573480"></a>Comment Syntax</h3></div></div></div> +<p> + The <acronym class="acronym">BIND</acronym> 9 comment syntax allows for + comments to appear + anywhere that whitespace may appear in a <acronym class="acronym">BIND</acronym> configuration + file. To appeal to programmers of all kinds, they can be written + in the C, C++, or shell/perl style. + </p> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2573495"></a>Syntax</h4></div></div></div> +<p> + </p> +<pre class="programlisting">/* This is a <acronym class="acronym">BIND</acronym> comment as in C */</pre> +<p> + </p> +<pre class="programlisting">// This is a <acronym class="acronym">BIND</acronym> comment as in C++</pre> +<p> + </p> +<pre class="programlisting"># This is a <acronym class="acronym">BIND</acronym> comment as in common UNIX shells and perl</pre> +<p> + </p> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2573525"></a>Definition and Usage</h4></div></div></div> +<p> + Comments may appear anywhere that whitespace may appear in + a <acronym class="acronym">BIND</acronym> configuration file. + </p> +<p> + C-style comments start with the two characters /* (slash, + star) and end with */ (star, slash). Because they are completely + delimited with these characters, they can be used to comment only + a portion of a line or to span multiple lines. + </p> +<p> + C-style comments cannot be nested. For example, the following + is not valid because the entire comment ends with the first */: + </p> +<p> + +</p> +<pre class="programlisting">/* This is the start of a comment. + This is still part of the comment. +/* This is an incorrect attempt at nesting a comment. */ + This is no longer in any comment. */ +</pre> +<p> + + </p> +<p> + C++-style comments start with the two characters // (slash, + slash) and continue to the end of the physical line. They cannot + be continued across multiple physical lines; to have one logical + comment span multiple lines, each line must use the // pair. + </p> +<p> + For example: + </p> +<p> + +</p> +<pre class="programlisting">// This is the start of a comment. The next line +// is a new comment, even though it is logically +// part of the previous comment. +</pre> +<p> + + </p> +<p> + Shell-style (or perl-style, if you prefer) comments start + with the character <code class="literal">#</code> (number sign) + and continue to the end of the + physical line, as in C++ comments. + </p> +<p> + For example: + </p> +<p> + +</p> +<pre class="programlisting"># This is the start of a comment. The next line +# is a new comment, even though it is logically +# part of the previous comment. +</pre> +<p> + + </p> +<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Warning</h3> +<p> + You cannot use the semicolon (`;') character + to start a comment such as you would in a zone file. The + semicolon indicates the end of a configuration + statement. + </p> +</div> +</div> +</div> +</div> +<div class="sect1" lang="en"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="Configuration_File_Grammar"></a>Configuration File Grammar</h2></div></div></div> +<p> + A <acronym class="acronym">BIND</acronym> 9 configuration consists of + statements and comments. + Statements end with a semicolon. Statements and comments are the + only elements that can appear without enclosing braces. Many + statements contain a block of sub-statements, which are also + terminated with a semicolon. + </p> +<p> + The following statements are supported: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p><span><strong class="command">acl</strong></span></p> + </td> +<td> + <p> + defines a named IP address + matching list, for access control and other uses. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">controls</strong></span></p> + </td> +<td> + <p> + declares control channels to be used + by the <span><strong class="command">rndc</strong></span> utility. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">include</strong></span></p> + </td> +<td> + <p> + includes a file. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">key</strong></span></p> + </td> +<td> + <p> + specifies key information for use in + authentication and authorization using TSIG. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">logging</strong></span></p> + </td> +<td> + <p> + specifies what the server logs, and where + the log messages are sent. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">lwres</strong></span></p> + </td> +<td> + <p> + configures <span><strong class="command">named</strong></span> to + also act as a light-weight resolver daemon (<span><strong class="command">lwresd</strong></span>). + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">masters</strong></span></p> + </td> +<td> + <p> + defines a named masters list for + inclusion in stub and slave zone masters clauses. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">options</strong></span></p> + </td> +<td> + <p> + controls global server configuration + options and sets defaults for other statements. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">server</strong></span></p> + </td> +<td> + <p> + sets certain configuration options on + a per-server basis. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">trusted-keys</strong></span></p> + </td> +<td> + <p> + defines trusted DNSSEC keys. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">view</strong></span></p> + </td> +<td> + <p> + defines a view. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">zone</strong></span></p> + </td> +<td> + <p> + defines a zone. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + The <span><strong class="command">logging</strong></span> and + <span><strong class="command">options</strong></span> statements may only occur once + per + configuration. + </p> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2574092"></a><span><strong class="command">acl</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting"><span><strong class="command">acl</strong></span> acl-name { + address_match_list +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="acl"></a><span><strong class="command">acl</strong></span> Statement Definition and + Usage</h3></div></div></div> +<p> + The <span><strong class="command">acl</strong></span> statement assigns a symbolic + name to an address match list. It gets its name from a primary + use of address match lists: Access Control Lists (ACLs). + </p> +<p> + Note that an address match list's name must be defined + with <span><strong class="command">acl</strong></span> before it can be used + elsewhere; no + forward references are allowed. + </p> +<p> + The following ACLs are built-in: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p><span><strong class="command">any</strong></span></p> + </td> +<td> + <p> + Matches all hosts. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">none</strong></span></p> + </td> +<td> + <p> + Matches no hosts. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">localhost</strong></span></p> + </td> +<td> + <p> + Matches the IPv4 and IPv6 addresses of all network + interfaces on the system. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">localnets</strong></span></p> + </td> +<td> + <p> + Matches any host on an IPv4 or IPv6 network + for which the system has an interface. + Some systems do not provide a way to determine the prefix + lengths of + local IPv6 addresses. + In such a case, <span><strong class="command">localnets</strong></span> + only matches the local + IPv6 addresses, just like <span><strong class="command">localhost</strong></span>. + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2574282"></a><span><strong class="command">controls</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting"><span><strong class="command">controls</strong></span> { + [ inet ( ip_addr | * ) [ port ip_port ] allow { <em class="replaceable"><code> address_match_list </code></em> } + keys { <em class="replaceable"><code>key_list</code></em> }; ] + [ inet ...; ] + [ unix <em class="replaceable"><code>path</code></em> perm <em class="replaceable"><code>number</code></em> owner <em class="replaceable"><code>number</code></em> group <em class="replaceable"><code>number</code></em> keys { <em class="replaceable"><code>key_list</code></em> }; ] + [ unix ...; ] +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="controls_statement_definition_and_usage"></a><span><strong class="command">controls</strong></span> Statement Definition and + Usage</h3></div></div></div> +<p> + The <span><strong class="command">controls</strong></span> statement declares control + channels to be used by system administrators to control the + operation of the name server. These control channels are + used by the <span><strong class="command">rndc</strong></span> utility to send + commands to and retrieve non-DNS results from a name server. + </p> +<p> + An <span><strong class="command">inet</strong></span> control channel is a TCP socket + listening at the specified <span><strong class="command">ip_port</strong></span> on the + specified <span><strong class="command">ip_addr</strong></span>, which can be an IPv4 or IPv6 + address. An <span><strong class="command">ip_addr</strong></span> of <code class="literal">*</code> (asterisk) is + interpreted as the IPv4 wildcard address; connections will be + accepted on any of the system's IPv4 addresses. + To listen on the IPv6 wildcard address, + use an <span><strong class="command">ip_addr</strong></span> of <code class="literal">::</code>. + If you will only use <span><strong class="command">rndc</strong></span> on the local host, + using the loopback address (<code class="literal">127.0.0.1</code> + or <code class="literal">::1</code>) is recommended for maximum security. + </p> +<p> + If no port is specified, port 953 is used. The asterisk + "<code class="literal">*</code>" cannot be used for <span><strong class="command">ip_port</strong></span>. + </p> +<p> + The ability to issue commands over the control channel is + restricted by the <span><strong class="command">allow</strong></span> and + <span><strong class="command">keys</strong></span> clauses. + Connections to the control channel are permitted based on the + <span><strong class="command">address_match_list</strong></span>. This is for simple + IP address based filtering only; any <span><strong class="command">key_id</strong></span> + elements of the <span><strong class="command">address_match_list</strong></span> + are ignored. + </p> +<p> + A <span><strong class="command">unix</strong></span> control channel is a UNIX domain + socket listening at the specified path in the file system. + Access to the socket is specified by the <span><strong class="command">perm</strong></span>, + <span><strong class="command">owner</strong></span> and <span><strong class="command">group</strong></span> clauses. + Note on some platforms (SunOS and Solaris) the permissions + (<span><strong class="command">perm</strong></span>) are applied to the parent directory + as the permissions on the socket itself are ignored. + </p> +<p> + The primary authorization mechanism of the command + channel is the <span><strong class="command">key_list</strong></span>, which + contains a list of <span><strong class="command">key_id</strong></span>s. + Each <span><strong class="command">key_id</strong></span> in the <span><strong class="command">key_list</strong></span> + is authorized to execute commands over the control channel. + See <a href="Bv9ARM.ch03.html#rndc">Remote Name Daemon Control application</a> in <a href="Bv9ARM.ch03.html#admin_tools" title="Administrative Tools">the section called “Administrative Tools”</a>) + for information about configuring keys in <span><strong class="command">rndc</strong></span>. + </p> +<p> + If no <span><strong class="command">controls</strong></span> statement is present, + <span><strong class="command">named</strong></span> will set up a default + control channel listening on the loopback address 127.0.0.1 + and its IPv6 counterpart ::1. + In this case, and also when the <span><strong class="command">controls</strong></span> statement + is present but does not have a <span><strong class="command">keys</strong></span> clause, + <span><strong class="command">named</strong></span> will attempt to load the command channel key + from the file <code class="filename">rndc.key</code> in + <code class="filename">/etc</code> (or whatever <code class="varname">sysconfdir</code> + was specified as when <acronym class="acronym">BIND</acronym> was built). + To create a <code class="filename">rndc.key</code> file, run + <strong class="userinput"><code>rndc-confgen -a</code></strong>. + </p> +<p> + The <code class="filename">rndc.key</code> feature was created to + ease the transition of systems from <acronym class="acronym">BIND</acronym> 8, + which did not have digital signatures on its command channel + messages and thus did not have a <span><strong class="command">keys</strong></span> clause. + + It makes it possible to use an existing <acronym class="acronym">BIND</acronym> 8 + configuration file in <acronym class="acronym">BIND</acronym> 9 unchanged, + and still have <span><strong class="command">rndc</strong></span> work the same way + <span><strong class="command">ndc</strong></span> worked in BIND 8, simply by executing the + command <strong class="userinput"><code>rndc-confgen -a</code></strong> after BIND 9 is + installed. + </p> +<p> + Since the <code class="filename">rndc.key</code> feature + is only intended to allow the backward-compatible usage of + <acronym class="acronym">BIND</acronym> 8 configuration files, this + feature does not + have a high degree of configurability. You cannot easily change + the key name or the size of the secret, so you should make a + <code class="filename">rndc.conf</code> with your own key if you + wish to change + those things. The <code class="filename">rndc.key</code> file + also has its + permissions set such that only the owner of the file (the user that + <span><strong class="command">named</strong></span> is running as) can access it. + If you + desire greater flexibility in allowing other users to access + <span><strong class="command">rndc</strong></span> commands, then you need to create + a + <code class="filename">rndc.conf</code> file and make it group + readable by a group + that contains the users who should have access. + </p> +<p> + To disable the command channel, use an empty + <span><strong class="command">controls</strong></span> statement: + <span><strong class="command">controls { };</strong></span>. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2574711"></a><span><strong class="command">include</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting">include <em class="replaceable"><code>filename</code></em>;</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2574726"></a><span><strong class="command">include</strong></span> Statement Definition and + Usage</h3></div></div></div> +<p> + The <span><strong class="command">include</strong></span> statement inserts the + specified file at the point where the <span><strong class="command">include</strong></span> + statement is encountered. The <span><strong class="command">include</strong></span> + statement facilitates the administration of configuration + files + by permitting the reading or writing of some things but not + others. For example, the statement could include private keys + that are readable only by the name server. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2574749"></a><span><strong class="command">key</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting">key <em class="replaceable"><code>key_id</code></em> { + algorithm <em class="replaceable"><code>string</code></em>; + secret <em class="replaceable"><code>string</code></em>; +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2574771"></a><span><strong class="command">key</strong></span> Statement Definition and Usage</h3></div></div></div> +<p> + The <span><strong class="command">key</strong></span> statement defines a shared + secret key for use with TSIG (see <a href="Bv9ARM.ch04.html#tsig" title="TSIG">the section called “TSIG”</a>) + or the command channel + (see <a href="Bv9ARM.ch06.html#controls_statement_definition_and_usage" title="controls Statement Definition and + Usage">the section called “<span><strong class="command">controls</strong></span> Statement Definition and + Usage”</a>). + </p> +<p> + The <span><strong class="command">key</strong></span> statement can occur at the + top level + of the configuration file or inside a <span><strong class="command">view</strong></span> + statement. Keys defined in top-level <span><strong class="command">key</strong></span> + statements can be used in all views. Keys intended for use in + a <span><strong class="command">controls</strong></span> statement + (see <a href="Bv9ARM.ch06.html#controls_statement_definition_and_usage" title="controls Statement Definition and + Usage">the section called “<span><strong class="command">controls</strong></span> Statement Definition and + Usage”</a>) + must be defined at the top level. + </p> +<p> + The <em class="replaceable"><code>key_id</code></em>, also known as the + key name, is a domain name uniquely identifying the key. It can + be used in a <span><strong class="command">server</strong></span> + statement to cause requests sent to that + server to be signed with this key, or in address match lists to + verify that incoming requests have been signed with a key + matching this name, algorithm, and secret. + </p> +<p> + The <em class="replaceable"><code>algorithm_id</code></em> is a string + that specifies a security/authentication algorithm. Named + supports <code class="literal">hmac-md5</code>, + <code class="literal">hmac-sha1</code>, <code class="literal">hmac-sha224</code>, + <code class="literal">hmac-sha256</code>, <code class="literal">hmac-sha384</code> + and <code class="literal">hmac-sha512</code> TSIG authentication. + Truncated hashes are supported by appending the minimum + number of required bits preceded by a dash, e.g. + <code class="literal">hmac-sha1-80</code>. The + <em class="replaceable"><code>secret_string</code></em> is the secret + to be used by the algorithm, and is treated as a base-64 + encoded string. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2574930"></a><span><strong class="command">logging</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting"><span><strong class="command">logging</strong></span> { + [ <span><strong class="command">channel</strong></span> <em class="replaceable"><code>channel_name</code></em> { + ( <span><strong class="command">file</strong></span> <em class="replaceable"><code>path name</code></em> + [ <span><strong class="command">versions</strong></span> ( <em class="replaceable"><code>number</code></em> | <span><strong class="command">unlimited</strong></span> ) ] + [ <span><strong class="command">size</strong></span> <em class="replaceable"><code>size spec</code></em> ] + | <span><strong class="command">syslog</strong></span> <em class="replaceable"><code>syslog_facility</code></em> + | <span><strong class="command">stderr</strong></span> + | <span><strong class="command">null</strong></span> ); + [ <span><strong class="command">severity</strong></span> (<code class="option">critical</code> | <code class="option">error</code> | <code class="option">warning</code> | <code class="option">notice</code> | + <code class="option">info</code> | <code class="option">debug</code> [ <em class="replaceable"><code>level</code></em> ] | <code class="option">dynamic</code> ); ] + [ <span><strong class="command">print-category</strong></span> <code class="option">yes</code> or <code class="option">no</code>; ] + [ <span><strong class="command">print-severity</strong></span> <code class="option">yes</code> or <code class="option">no</code>; ] + [ <span><strong class="command">print-time</strong></span> <code class="option">yes</code> or <code class="option">no</code>; ] + }; ] + [ <span><strong class="command">category</strong></span> <em class="replaceable"><code>category_name</code></em> { + <em class="replaceable"><code>channel_name</code></em> ; [ <em class="replaceable"><code>channel_name</code></em> ; ... ] + }; ] + ... +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2575056"></a><span><strong class="command">logging</strong></span> Statement Definition and + Usage</h3></div></div></div> +<p> + The <span><strong class="command">logging</strong></span> statement configures a + wide + variety of logging options for the name server. Its <span><strong class="command">channel</strong></span> phrase + associates output methods, format options and severity levels with + a name that can then be used with the <span><strong class="command">category</strong></span> phrase + to select how various classes of messages are logged. + </p> +<p> + Only one <span><strong class="command">logging</strong></span> statement is used to + define + as many channels and categories as are wanted. If there is no <span><strong class="command">logging</strong></span> statement, + the logging configuration will be: + </p> +<pre class="programlisting">logging { + category default { default_syslog; default_debug; }; + category unmatched { null; }; +}; +</pre> +<p> + In <acronym class="acronym">BIND</acronym> 9, the logging configuration + is only established when + the entire configuration file has been parsed. In <acronym class="acronym">BIND</acronym> 8, it was + established as soon as the <span><strong class="command">logging</strong></span> + statement + was parsed. When the server is starting up, all logging messages + regarding syntax errors in the configuration file go to the default + channels, or to standard error if the "<code class="option">-g</code>" option + was specified. + </p> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2575108"></a>The <span><strong class="command">channel</strong></span> Phrase</h4></div></div></div> +<p> + All log output goes to one or more <span class="emphasis"><em>channels</em></span>; + you can make as many of them as you want. + </p> +<p> + Every channel definition must include a destination clause that + says whether messages selected for the channel go to a file, to a + particular syslog facility, to the standard error stream, or are + discarded. It can optionally also limit the message severity level + that will be accepted by the channel (the default is + <span><strong class="command">info</strong></span>), and whether to include a + <span><strong class="command">named</strong></span>-generated time stamp, the + category name + and/or severity level (the default is not to include any). + </p> +<p> + The <span><strong class="command">null</strong></span> destination clause + causes all messages sent to the channel to be discarded; + in that case, other options for the channel are meaningless. + </p> +<p> + The <span><strong class="command">file</strong></span> destination clause directs + the channel + to a disk file. It can include limitations + both on how large the file is allowed to become, and how many + versions + of the file will be saved each time the file is opened. + </p> +<p> + If you use the <span><strong class="command">versions</strong></span> log file + option, then + <span><strong class="command">named</strong></span> will retain that many backup + versions of the file by + renaming them when opening. For example, if you choose to keep + three old versions + of the file <code class="filename">lamers.log</code>, then just + before it is opened + <code class="filename">lamers.log.1</code> is renamed to + <code class="filename">lamers.log.2</code>, <code class="filename">lamers.log.0</code> is renamed + to <code class="filename">lamers.log.1</code>, and <code class="filename">lamers.log</code> is + renamed to <code class="filename">lamers.log.0</code>. + You can say <span><strong class="command">versions unlimited</strong></span> to + not limit + the number of versions. + If a <span><strong class="command">size</strong></span> option is associated with + the log file, + then renaming is only done when the file being opened exceeds the + indicated size. No backup versions are kept by default; any + existing + log file is simply appended. + </p> +<p> + The <span><strong class="command">size</strong></span> option for files is used + to limit log + growth. If the file ever exceeds the size, then <span><strong class="command">named</strong></span> will + stop writing to the file unless it has a <span><strong class="command">versions</strong></span> option + associated with it. If backup versions are kept, the files are + rolled as + described above and a new one begun. If there is no + <span><strong class="command">versions</strong></span> option, no more data will + be written to the log + until some out-of-band mechanism removes or truncates the log to + less than the + maximum size. The default behavior is not to limit the size of + the + file. + </p> +<p> + Example usage of the <span><strong class="command">size</strong></span> and + <span><strong class="command">versions</strong></span> options: + </p> +<pre class="programlisting">channel an_example_channel { + file "example.log" versions 3 size 20m; + print-time yes; + print-category yes; +}; +</pre> +<p> + The <span><strong class="command">syslog</strong></span> destination clause + directs the + channel to the system log. Its argument is a + syslog facility as described in the <span><strong class="command">syslog</strong></span> man + page. Known facilities are <span><strong class="command">kern</strong></span>, <span><strong class="command">user</strong></span>, + <span><strong class="command">mail</strong></span>, <span><strong class="command">daemon</strong></span>, <span><strong class="command">auth</strong></span>, + <span><strong class="command">syslog</strong></span>, <span><strong class="command">lpr</strong></span>, <span><strong class="command">news</strong></span>, + <span><strong class="command">uucp</strong></span>, <span><strong class="command">cron</strong></span>, <span><strong class="command">authpriv</strong></span>, + <span><strong class="command">ftp</strong></span>, <span><strong class="command">local0</strong></span>, <span><strong class="command">local1</strong></span>, + <span><strong class="command">local2</strong></span>, <span><strong class="command">local3</strong></span>, <span><strong class="command">local4</strong></span>, + <span><strong class="command">local5</strong></span>, <span><strong class="command">local6</strong></span> and + <span><strong class="command">local7</strong></span>, however not all facilities + are supported on + all operating systems. + How <span><strong class="command">syslog</strong></span> will handle messages + sent to + this facility is described in the <span><strong class="command">syslog.conf</strong></span> man + page. If you have a system which uses a very old version of <span><strong class="command">syslog</strong></span> that + only uses two arguments to the <span><strong class="command">openlog()</strong></span> function, + then this clause is silently ignored. + </p> +<p> + The <span><strong class="command">severity</strong></span> clause works like <span><strong class="command">syslog</strong></span>'s + "priorities", except that they can also be used if you are writing + straight to a file rather than using <span><strong class="command">syslog</strong></span>. + Messages which are not at least of the severity level given will + not be selected for the channel; messages of higher severity + levels + will be accepted. + </p> +<p> + If you are using <span><strong class="command">syslog</strong></span>, then the <span><strong class="command">syslog.conf</strong></span> priorities + will also determine what eventually passes through. For example, + defining a channel facility and severity as <span><strong class="command">daemon</strong></span> and <span><strong class="command">debug</strong></span> but + only logging <span><strong class="command">daemon.warning</strong></span> via <span><strong class="command">syslog.conf</strong></span> will + cause messages of severity <span><strong class="command">info</strong></span> and + <span><strong class="command">notice</strong></span> to + be dropped. If the situation were reversed, with <span><strong class="command">named</strong></span> writing + messages of only <span><strong class="command">warning</strong></span> or higher, + then <span><strong class="command">syslogd</strong></span> would + print all messages it received from the channel. + </p> +<p> + The <span><strong class="command">stderr</strong></span> destination clause + directs the + channel to the server's standard error stream. This is intended + for + use when the server is running as a foreground process, for + example + when debugging a configuration. + </p> +<p> + The server can supply extensive debugging information when + it is in debugging mode. If the server's global debug level is + greater + than zero, then debugging mode will be active. The global debug + level is set either by starting the <span><strong class="command">named</strong></span> server + with the <code class="option">-d</code> flag followed by a positive integer, + or by running <span><strong class="command">rndc trace</strong></span>. + The global debug level + can be set to zero, and debugging mode turned off, by running <span><strong class="command">rndc +notrace</strong></span>. All debugging messages in the server have a debug + level, and higher debug levels give more detailed output. Channels + that specify a specific debug severity, for example: + </p> +<pre class="programlisting">channel specific_debug_level { + file "foo"; + severity debug 3; +}; +</pre> +<p> + will get debugging output of level 3 or less any time the + server is in debugging mode, regardless of the global debugging + level. Channels with <span><strong class="command">dynamic</strong></span> + severity use the + server's global debug level to determine what messages to print. + </p> +<p> + If <span><strong class="command">print-time</strong></span> has been turned on, + then + the date and time will be logged. <span><strong class="command">print-time</strong></span> may + be specified for a <span><strong class="command">syslog</strong></span> channel, + but is usually + pointless since <span><strong class="command">syslog</strong></span> also prints + the date and + time. If <span><strong class="command">print-category</strong></span> is + requested, then the + category of the message will be logged as well. Finally, if <span><strong class="command">print-severity</strong></span> is + on, then the severity level of the message will be logged. The <span><strong class="command">print-</strong></span> options may + be used in any combination, and will always be printed in the + following + order: time, category, severity. Here is an example where all + three <span><strong class="command">print-</strong></span> options + are on: + </p> +<p> + <code class="computeroutput">28-Feb-2000 15:05:32.863 general: notice: running</code> + </p> +<p> + There are four predefined channels that are used for + <span><strong class="command">named</strong></span>'s default logging as follows. + How they are + used is described in <a href="Bv9ARM.ch06.html#the_category_phrase" title="The category Phrase">the section called “The <span><strong class="command">category</strong></span> Phrase”</a>. + </p> +<pre class="programlisting">channel default_syslog { + syslog daemon; // send to syslog's daemon + // facility + severity info; // only send priority info + // and higher +}; + +channel default_debug { + file "named.run"; // write to named.run in + // the working directory + // Note: stderr is used instead + // of "named.run" + // if the server is started + // with the '-f' option. + severity dynamic; // log at the server's + // current debug level +}; + +channel default_stderr { + stderr; // writes to stderr + severity info; // only send priority info + // and higher +}; + +channel null { + null; // toss anything sent to + // this channel +}; +</pre> +<p> + The <span><strong class="command">default_debug</strong></span> channel has the + special + property that it only produces output when the server's debug + level is + nonzero. It normally writes to a file called <code class="filename">named.run</code> + in the server's working directory. + </p> +<p> + For security reasons, when the "<code class="option">-u</code>" + command line option is used, the <code class="filename">named.run</code> file + is created only after <span><strong class="command">named</strong></span> has + changed to the + new UID, and any debug output generated while <span><strong class="command">named</strong></span> is + starting up and still running as root is discarded. If you need + to capture this output, you must run the server with the "<code class="option">-g</code>" + option and redirect standard error to a file. + </p> +<p> + Once a channel is defined, it cannot be redefined. Thus you + cannot alter the built-in channels directly, but you can modify + the default logging by pointing categories at channels you have + defined. + </p> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="the_category_phrase"></a>The <span><strong class="command">category</strong></span> Phrase</h4></div></div></div> +<p> + There are many categories, so you can send the logs you want + to see wherever you want, without seeing logs you don't want. If + you don't specify a list of channels for a category, then log + messages + in that category will be sent to the <span><strong class="command">default</strong></span> category + instead. If you don't specify a default category, the following + "default default" is used: + </p> +<pre class="programlisting">category default { default_syslog; default_debug; }; +</pre> +<p> + As an example, let's say you want to log security events to + a file, but you also want keep the default logging behavior. You'd + specify the following: + </p> +<pre class="programlisting">channel my_security_channel { + file "my_security_file"; + severity info; +}; +category security { + my_security_channel; + default_syslog; + default_debug; +};</pre> +<p> + To discard all messages in a category, specify the <span><strong class="command">null</strong></span> channel: + </p> +<pre class="programlisting">category xfer-out { null; }; +category notify { null; }; +</pre> +<p> + Following are the available categories and brief descriptions + of the types of log information they contain. More + categories may be added in future <acronym class="acronym">BIND</acronym> releases. + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p><span><strong class="command">default</strong></span></p> + </td> +<td> + <p> + The default category defines the logging + options for those categories where no specific + configuration has been + defined. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">general</strong></span></p> + </td> +<td> + <p> + The catch-all. Many things still aren't + classified into categories, and they all end up here. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">database</strong></span></p> + </td> +<td> + <p> + Messages relating to the databases used + internally by the name server to store zone and cache + data. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">security</strong></span></p> + </td> +<td> + <p> + Approval and denial of requests. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">config</strong></span></p> + </td> +<td> + <p> + Configuration file parsing and processing. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">resolver</strong></span></p> + </td> +<td> + <p> + DNS resolution, such as the recursive + lookups performed on behalf of clients by a caching name + server. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">xfer-in</strong></span></p> + </td> +<td> + <p> + Zone transfers the server is receiving. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">xfer-out</strong></span></p> + </td> +<td> + <p> + Zone transfers the server is sending. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">notify</strong></span></p> + </td> +<td> + <p> + The NOTIFY protocol. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">client</strong></span></p> + </td> +<td> + <p> + Processing of client requests. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">unmatched</strong></span></p> + </td> +<td> + <p> + Messages that named was unable to determine the + class of or for which there was no matching <span><strong class="command">view</strong></span>. + A one line summary is also logged to the <span><strong class="command">client</strong></span> category. + This category is best sent to a file or stderr, by + default it is sent to + the <span><strong class="command">null</strong></span> channel. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">network</strong></span></p> + </td> +<td> + <p> + Network operations. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">update</strong></span></p> + </td> +<td> + <p> + Dynamic updates. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">update-security</strong></span></p> + </td> +<td> + <p> + Approval and denial of update requests. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">queries</strong></span></p> + </td> +<td> + <p> + Specify where queries should be logged to. + </p> + <p> + At startup, specifying the category <span><strong class="command">queries</strong></span> will also + enable query logging unless <span><strong class="command">querylog</strong></span> option has been + specified. + </p> + <p> + The query log entry reports the client's IP address and + port number, and the + query name, class and type. It also reports whether the + Recursion Desired + flag was set (+ if set, - if not set), EDNS was in use + (E) or if the + query was signed (S). + </p> + <p> + <code class="computeroutput">client 127.0.0.1#62536: query: www.example.com IN AAAA +SE</code> + </p> + <p> + <code class="computeroutput">client ::1#62537: query: www.example.net IN AAAA -SE</code> + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">dispatch</strong></span></p> + </td> +<td> + <p> + Dispatching of incoming packets to the + server modules where they are to be processed. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">dnssec</strong></span></p> + </td> +<td> + <p> + DNSSEC and TSIG protocol processing. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">lame-servers</strong></span></p> + </td> +<td> + <p> + Lame servers. These are misconfigurations + in remote servers, discovered by BIND 9 when trying to + query + those servers during resolution. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">delegation-only</strong></span></p> + </td> +<td> + <p> + Delegation only. Logs queries that have have + been forced to NXDOMAIN as the result of a + delegation-only zone or + a <span><strong class="command">delegation-only</strong></span> in a + hint or stub zone declaration. + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2576406"></a><span><strong class="command">lwres</strong></span> Statement Grammar</h3></div></div></div> +<p> + This is the grammar of the <span><strong class="command">lwres</strong></span> + statement in the <code class="filename">named.conf</code> file: + </p> +<pre class="programlisting"><span><strong class="command">lwres</strong></span> { + [<span class="optional"> listen-on { <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> view <em class="replaceable"><code>view_name</code></em>; </span>] + [<span class="optional"> search { <em class="replaceable"><code>domain_name</code></em> ; [<span class="optional"> <em class="replaceable"><code>domain_name</code></em> ; ... </span>] }; </span>] + [<span class="optional"> ndots <em class="replaceable"><code>number</code></em>; </span>] +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2576480"></a><span><strong class="command">lwres</strong></span> Statement Definition and Usage</h3></div></div></div> +<p> + The <span><strong class="command">lwres</strong></span> statement configures the + name + server to also act as a lightweight resolver server. (See + <a href="Bv9ARM.ch05.html#lwresd" title="Running a Resolver Daemon">the section called “Running a Resolver Daemon”</a>.) There may be multiple + <span><strong class="command">lwres</strong></span> statements configuring + lightweight resolver servers with different properties. + </p> +<p> + The <span><strong class="command">listen-on</strong></span> statement specifies a + list of + addresses (and ports) that this instance of a lightweight resolver + daemon + should accept requests on. If no port is specified, port 921 is + used. + If this statement is omitted, requests will be accepted on + 127.0.0.1, + port 921. + </p> +<p> + The <span><strong class="command">view</strong></span> statement binds this + instance of a + lightweight resolver daemon to a view in the DNS namespace, so that + the + response will be constructed in the same manner as a normal DNS + query + matching this view. If this statement is omitted, the default view + is + used, and if there is no default view, an error is triggered. + </p> +<p> + The <span><strong class="command">search</strong></span> statement is equivalent to + the + <span><strong class="command">search</strong></span> statement in + <code class="filename">/etc/resolv.conf</code>. It provides a + list of domains + which are appended to relative names in queries. + </p> +<p> + The <span><strong class="command">ndots</strong></span> statement is equivalent to + the + <span><strong class="command">ndots</strong></span> statement in + <code class="filename">/etc/resolv.conf</code>. It indicates the + minimum + number of dots in a relative domain name that should result in an + exact match lookup before search path elements are appended. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2576544"></a><span><strong class="command">masters</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting"> +<span><strong class="command">masters</strong></span> <em class="replaceable"><code>name</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] { ( <em class="replaceable"><code>masters_list</code></em> | <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] [<span class="optional">key <em class="replaceable"><code>key</code></em></span>] ) ; [<span class="optional">...</span>] }; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2576587"></a><span><strong class="command">masters</strong></span> Statement Definition and + Usage</h3></div></div></div> +<p><span><strong class="command">masters</strong></span> + lists allow for a common set of masters to be easily used by + multiple stub and slave zones. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2576602"></a><span><strong class="command">options</strong></span> Statement Grammar</h3></div></div></div> +<p> + This is the grammar of the <span><strong class="command">options</strong></span> + statement in the <code class="filename">named.conf</code> file: + </p> +<pre class="programlisting">options { + [<span class="optional"> version <em class="replaceable"><code>version_string</code></em>; </span>] + [<span class="optional"> hostname <em class="replaceable"><code>hostname_string</code></em>; </span>] + [<span class="optional"> server-id <em class="replaceable"><code>server_id_string</code></em>; </span>] + [<span class="optional"> directory <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> key-directory <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> named-xfer <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> tkey-domain <em class="replaceable"><code>domainname</code></em>; </span>] + [<span class="optional"> tkey-dhkey <em class="replaceable"><code>key_name</code></em> <em class="replaceable"><code>key_tag</code></em>; </span>] + [<span class="optional"> cache-file <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> dump-file <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> memstatistics-file <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> pid-file <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> recursing-file <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> statistics-file <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> zone-statistics <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> auth-nxdomain <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> deallocate-on-exit <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> dialup <em class="replaceable"><code>dialup_option</code></em>; </span>] + [<span class="optional"> fake-iquery <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> fetch-glue <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> flush-zones-on-shutdown <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> has-old-clients <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> host-statistics <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> host-statistics-max <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> minimal-responses <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> multiple-cnames <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> notify <em class="replaceable"><code>yes_or_no</code></em> | <em class="replaceable"><code>explicit</code></em> | <em class="replaceable"><code>master-only</code></em>; </span>] + [<span class="optional"> recursion <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> rfc2308-type1 <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> use-id-pool <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> maintain-ixfr-base <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> dnssec-enable <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> dnssec-validation <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> dnssec-lookaside <em class="replaceable"><code>domain</code></em> trust-anchor <em class="replaceable"><code>domain</code></em>; </span>] + [<span class="optional"> dnssec-must-be-secure <em class="replaceable"><code>domain yes_or_no</code></em>; </span>] + [<span class="optional"> dnssec-accept-expired <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> forward ( <em class="replaceable"><code>only</code></em> | <em class="replaceable"><code>first</code></em> ); </span>] + [<span class="optional"> forwarders { [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> dual-stack-servers [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] { + ( <em class="replaceable"><code>domain_name</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] | + <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ) ; + ... }; </span>] + [<span class="optional"> check-names ( <em class="replaceable"><code>master</code></em> | <em class="replaceable"><code>slave</code></em> | <em class="replaceable"><code>response</code></em> ) + ( <em class="replaceable"><code>warn</code></em> | <em class="replaceable"><code>fail</code></em> | <em class="replaceable"><code>ignore</code></em> ); </span>] + [<span class="optional"> check-mx ( <em class="replaceable"><code>warn</code></em> | <em class="replaceable"><code>fail</code></em> | <em class="replaceable"><code>ignore</code></em> ); </span>] + [<span class="optional"> check-wildcard <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> check-integrity <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> check-mx-cname ( <em class="replaceable"><code>warn</code></em> | <em class="replaceable"><code>fail</code></em> | <em class="replaceable"><code>ignore</code></em> ); </span>] + [<span class="optional"> check-srv-cname ( <em class="replaceable"><code>warn</code></em> | <em class="replaceable"><code>fail</code></em> | <em class="replaceable"><code>ignore</code></em> ); </span>] + [<span class="optional"> check-sibling <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> allow-notify { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-query { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-query-cache { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-transfer { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-recursion { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-update { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-update-forwarding { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> update-check-ksk <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> allow-v6-synthesis { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> blackhole { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> avoid-v4-udp-ports { <em class="replaceable"><code>port_list</code></em> }; </span>] + [<span class="optional"> avoid-v6-udp-ports { <em class="replaceable"><code>port_list</code></em> }; </span>] + [<span class="optional"> listen-on [<span class="optional"> port <em class="replaceable"><code>ip_port</code></em> </span>] { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> listen-on-v6 [<span class="optional"> port <em class="replaceable"><code>ip_port</code></em> </span>] { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> query-source ( ( <em class="replaceable"><code>ip4_addr</code></em> | <em class="replaceable"><code>*</code></em> ) + [<span class="optional"> port ( <em class="replaceable"><code>ip_port</code></em> | <em class="replaceable"><code>*</code></em> ) </span>] | + [<span class="optional"> address ( <em class="replaceable"><code>ip4_addr</code></em> | <em class="replaceable"><code>*</code></em> ) </span>] + [<span class="optional"> port ( <em class="replaceable"><code>ip_port</code></em> | <em class="replaceable"><code>*</code></em> ) </span>] ) ; </span>] + [<span class="optional"> query-source-v6 ( ( <em class="replaceable"><code>ip6_addr</code></em> | <em class="replaceable"><code>*</code></em> ) + [<span class="optional"> port ( <em class="replaceable"><code>ip_port</code></em> | <em class="replaceable"><code>*</code></em> ) </span>] | + [<span class="optional"> address ( <em class="replaceable"><code>ip6_addr</code></em> | <em class="replaceable"><code>*</code></em> ) </span>] + [<span class="optional"> port ( <em class="replaceable"><code>ip_port</code></em> | <em class="replaceable"><code>*</code></em> ) </span>] ) ; </span>] + [<span class="optional"> max-transfer-time-in <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> max-transfer-time-out <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> max-transfer-idle-in <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> max-transfer-idle-out <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> tcp-clients <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> recursive-clients <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> serial-query-rate <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> serial-queries <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> tcp-listen-queue <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> transfer-format <em class="replaceable"><code>( one-answer | many-answers )</code></em>; </span>] + [<span class="optional"> transfers-in <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> transfers-out <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> transfers-per-ns <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> transfer-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> transfer-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> alt-transfer-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> alt-transfer-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> use-alt-transfer-source <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> notify-delay <em class="replaceable"><code>seconds</code></em> ; </span>] + [<span class="optional"> notify-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> notify-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> also-notify { <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> max-ixfr-log-size <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> max-journal-size <em class="replaceable"><code>size_spec</code></em>; </span>] + [<span class="optional"> coresize <em class="replaceable"><code>size_spec</code></em> ; </span>] + [<span class="optional"> datasize <em class="replaceable"><code>size_spec</code></em> ; </span>] + [<span class="optional"> files <em class="replaceable"><code>size_spec</code></em> ; </span>] + [<span class="optional"> stacksize <em class="replaceable"><code>size_spec</code></em> ; </span>] + [<span class="optional"> cleaning-interval <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> heartbeat-interval <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> interface-interval <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> statistics-interval <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> topology { <em class="replaceable"><code>address_match_list</code></em> }</span>]; + [<span class="optional"> sortlist { <em class="replaceable"><code>address_match_list</code></em> }</span>]; + [<span class="optional"> rrset-order { <em class="replaceable"><code>order_spec</code></em> ; [<span class="optional"> <em class="replaceable"><code>order_spec</code></em> ; ... </span>] </span>] }; + [<span class="optional"> lame-ttl <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> max-ncache-ttl <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> max-cache-ttl <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> sig-validity-interval <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> min-roots <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> use-ixfr <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> provide-ixfr <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> request-ixfr <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> treat-cr-as-space <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> min-refresh-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-refresh-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> min-retry-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-retry-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> port <em class="replaceable"><code>ip_port</code></em>; </span>] + [<span class="optional"> additional-from-auth <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> additional-from-cache <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> random-device <em class="replaceable"><code>path_name</code></em> ; </span>] + [<span class="optional"> max-cache-size <em class="replaceable"><code>size_spec</code></em> ; </span>] + [<span class="optional"> match-mapped-addresses <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> preferred-glue ( <em class="replaceable"><code>A</code></em> | <em class="replaceable"><code>AAAA</code></em> | <em class="replaceable"><code>NONE</code></em> ); </span>] + [<span class="optional"> edns-udp-size <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> max-udp-size <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> root-delegation-only [<span class="optional"> exclude { <em class="replaceable"><code>namelist</code></em> } </span>] ; </span>] + [<span class="optional"> querylog <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> disable-algorithms <em class="replaceable"><code>domain</code></em> { <em class="replaceable"><code>algorithm</code></em>; [<span class="optional"> <em class="replaceable"><code>algorithm</code></em>; </span>] }; </span>] + [<span class="optional"> acache-enable <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> acache-cleaning-interval <em class="replaceable"><code>number</code></em>; </span>] + [<span class="optional"> max-acache-size <em class="replaceable"><code>size_spec</code></em> ; </span>] + [<span class="optional"> clients-per-query <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-clients-per-query <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> masterfile-format (<code class="constant">text</code>|<code class="constant">raw</code>) ; </span>] + [<span class="optional"> empty-server <em class="replaceable"><code>name</code></em> ; </span>] + [<span class="optional"> empty-contact <em class="replaceable"><code>name</code></em> ; </span>] + [<span class="optional"> empty-zones-enable <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> disable-empty-zone <em class="replaceable"><code>zone_name</code></em> ; </span>] + [<span class="optional"> zero-no-soa-ttl <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> zero-no-soa-ttl-cache <em class="replaceable"><code>yes_or_no</code></em> ; </span>] +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="options"></a><span><strong class="command">options</strong></span> Statement Definition and + Usage</h3></div></div></div> +<p> + The <span><strong class="command">options</strong></span> statement sets up global + options + to be used by <acronym class="acronym">BIND</acronym>. This statement + may appear only + once in a configuration file. If there is no <span><strong class="command">options</strong></span> + statement, an options block with each option set to its default will + be used. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">directory</strong></span></span></dt> +<dd><p> + The working directory of the server. + Any non-absolute pathnames in the configuration file will be + taken + as relative to this directory. The default location for most + server + output files (e.g. <code class="filename">named.run</code>) + is this directory. + If a directory is not specified, the working directory + defaults to `<code class="filename">.</code>', the directory from + which the server + was started. The directory specified should be an absolute + path. + </p></dd> +<dt><span class="term"><span><strong class="command">key-directory</strong></span></span></dt> +<dd><p> + When performing dynamic update of secure zones, the + directory where the public and private key files should be + found, + if different than the current working directory. The + directory specified + must be an absolute path. + </p></dd> +<dt><span class="term"><span><strong class="command">named-xfer</strong></span></span></dt> +<dd><p> + <span class="emphasis"><em>This option is obsolete.</em></span> + It was used in <acronym class="acronym">BIND</acronym> 8 to + specify the pathname to the <span><strong class="command">named-xfer</strong></span> program. + In <acronym class="acronym">BIND</acronym> 9, no separate <span><strong class="command">named-xfer</strong></span> program is + needed; its functionality is built into the name server. + </p></dd> +<dt><span class="term"><span><strong class="command">tkey-domain</strong></span></span></dt> +<dd><p> + The domain appended to the names of all + shared keys generated with + <span><strong class="command">TKEY</strong></span>. When a client + requests a <span><strong class="command">TKEY</strong></span> exchange, it + may or may not specify + the desired name for the key. If present, the name of the + shared + key will be "<code class="varname">client specified part</code>" + + "<code class="varname">tkey-domain</code>". + Otherwise, the name of the shared key will be "<code class="varname">random hex +digits</code>" + "<code class="varname">tkey-domain</code>". In most cases, + the <span><strong class="command">domainname</strong></span> should be the + server's domain + name. + </p></dd> +<dt><span class="term"><span><strong class="command">tkey-dhkey</strong></span></span></dt> +<dd><p> + The Diffie-Hellman key used by the server + to generate shared keys with clients using the Diffie-Hellman + mode + of <span><strong class="command">TKEY</strong></span>. The server must be + able to load the + public and private keys from files in the working directory. + In + most cases, the keyname should be the server's host name. + </p></dd> +<dt><span class="term"><span><strong class="command">cache-file</strong></span></span></dt> +<dd><p> + This is for testing only. Do not use. + </p></dd> +<dt><span class="term"><span><strong class="command">dump-file</strong></span></span></dt> +<dd><p> + The pathname of the file the server dumps + the database to when instructed to do so with + <span><strong class="command">rndc dumpdb</strong></span>. + If not specified, the default is <code class="filename">named_dump.db</code>. + </p></dd> +<dt><span class="term"><span><strong class="command">memstatistics-file</strong></span></span></dt> +<dd> +<p> + The pathname of the file the server writes memory + usage statistics to on exit. If specified the + statistics will be written to the file on exit. + </p> +<p> + In <acronym class="acronym">BIND</acronym> 9.5 and later this will + default to <code class="filename">named.memstats</code>. + <acronym class="acronym">BIND</acronym> 9.5 will also introduce + <span><strong class="command">memstatistics</strong></span> to control the + writing. + </p> +</dd> +<dt><span class="term"><span><strong class="command">pid-file</strong></span></span></dt> +<dd><p> + The pathname of the file the server writes its process ID + in. If not specified, the default is <code class="filename">/var/run/named.pid</code>. + The pid-file is used by programs that want to send signals to + the running + name server. Specifying <span><strong class="command">pid-file none</strong></span> disables the + use of a PID file — no file will be written and any + existing one will be removed. Note that <span><strong class="command">none</strong></span> + is a keyword, not a filename, and therefore is not enclosed + in + double quotes. + </p></dd> +<dt><span class="term"><span><strong class="command">recursing-file</strong></span></span></dt> +<dd><p> + The pathname of the file the server dumps + the queries that are currently recursing when instructed + to do so with <span><strong class="command">rndc recursing</strong></span>. + If not specified, the default is <code class="filename">named.recursing</code>. + </p></dd> +<dt><span class="term"><span><strong class="command">statistics-file</strong></span></span></dt> +<dd><p> + The pathname of the file the server appends statistics + to when instructed to do so using <span><strong class="command">rndc stats</strong></span>. + If not specified, the default is <code class="filename">named.stats</code> in the + server's current directory. The format of the file is + described + in <a href="Bv9ARM.ch06.html#statsfile" title="The Statistics File">the section called “The Statistics File”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">port</strong></span></span></dt> +<dd><p> + The UDP/TCP port number the server uses for + receiving and sending DNS protocol traffic. + The default is 53. This option is mainly intended for server + testing; + a server using a port other than 53 will not be able to + communicate with + the global DNS. + </p></dd> +<dt><span class="term"><span><strong class="command">random-device</strong></span></span></dt> +<dd><p> + The source of entropy to be used by the server. Entropy is + primarily needed + for DNSSEC operations, such as TKEY transactions and dynamic + update of signed + zones. This options specifies the device (or file) from which + to read + entropy. If this is a file, operations requiring entropy will + fail when the + file has been exhausted. If not specified, the default value + is + <code class="filename">/dev/random</code> + (or equivalent) when present, and none otherwise. The + <span><strong class="command">random-device</strong></span> option takes + effect during + the initial configuration load at server startup time and + is ignored on subsequent reloads. + </p></dd> +<dt><span class="term"><span><strong class="command">preferred-glue</strong></span></span></dt> +<dd><p> + If specified, the listed type (A or AAAA) will be emitted + before other glue + in the additional section of a query response. + The default is not to prefer any type (NONE). + </p></dd> +<dt><span class="term"><span><strong class="command">root-delegation-only</strong></span></span></dt> +<dd> +<p> + Turn on enforcement of delegation-only in TLDs (top level domains) and root zones + with an optional + exclude list. + </p> +<p> + Note some TLDs are not delegation only (e.g. "DE", "LV", "US" + and "MUSEUM"). + </p> +<pre class="programlisting"> +options { + root-delegation-only exclude { "de"; "lv"; "us"; "museum"; }; +}; +</pre> +</dd> +<dt><span class="term"><span><strong class="command">disable-algorithms</strong></span></span></dt> +<dd><p> + Disable the specified DNSSEC algorithms at and below the + specified name. + Multiple <span><strong class="command">disable-algorithms</strong></span> + statements are allowed. + Only the most specific will be applied. + </p></dd> +<dt><span class="term"><span><strong class="command">dnssec-lookaside</strong></span></span></dt> +<dd><p> + When set, <span><strong class="command">dnssec-lookaside</strong></span> + provides the + validator with an alternate method to validate DNSKEY records + at the + top of a zone. When a DNSKEY is at or below a domain + specified by the + deepest <span><strong class="command">dnssec-lookaside</strong></span>, and + the normal dnssec validation + has left the key untrusted, the trust-anchor will be append to + the key + name and a DLV record will be looked up to see if it can + validate the + key. If the DLV record validates a DNSKEY (similarly to the + way a DS + record does) the DNSKEY RRset is deemed to be trusted. + </p></dd> +<dt><span class="term"><span><strong class="command">dnssec-must-be-secure</strong></span></span></dt> +<dd><p> + Specify hierarchies which must be or may not be secure (signed and + validated). + If <strong class="userinput"><code>yes</code></strong>, then named will only accept + answers if they + are secure. + If <strong class="userinput"><code>no</code></strong>, then normal dnssec validation + applies + allowing for insecure answers to be accepted. + The specified domain must be under a <span><strong class="command">trusted-key</strong></span> or + <span><strong class="command">dnssec-lookaside</strong></span> must be + active. + </p></dd> +</dl></div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="boolean_options"></a>Boolean Options</h4></div></div></div> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">auth-nxdomain</strong></span></span></dt> +<dd><p> + If <strong class="userinput"><code>yes</code></strong>, then the <span><strong class="command">AA</strong></span> bit + is always set on NXDOMAIN responses, even if the server is + not actually + authoritative. The default is <strong class="userinput"><code>no</code></strong>; + this is + a change from <acronym class="acronym">BIND</acronym> 8. If you + are using very old DNS software, you + may need to set it to <strong class="userinput"><code>yes</code></strong>. + </p></dd> +<dt><span class="term"><span><strong class="command">deallocate-on-exit</strong></span></span></dt> +<dd><p> + This option was used in <acronym class="acronym">BIND</acronym> + 8 to enable checking + for memory leaks on exit. <acronym class="acronym">BIND</acronym> 9 ignores the option and always performs + the checks. + </p></dd> +<dt><span class="term"><span><strong class="command">dialup</strong></span></span></dt> +<dd> +<p> + If <strong class="userinput"><code>yes</code></strong>, then the + server treats all zones as if they are doing zone transfers + across + a dial-on-demand dialup link, which can be brought up by + traffic + originating from this server. This has different effects + according + to zone type and concentrates the zone maintenance so that + it all + happens in a short interval, once every <span><strong class="command">heartbeat-interval</strong></span> and + hopefully during the one call. It also suppresses some of + the normal + zone maintenance traffic. The default is <strong class="userinput"><code>no</code></strong>. + </p> +<p> + The <span><strong class="command">dialup</strong></span> option + may also be specified in the <span><strong class="command">view</strong></span> and + <span><strong class="command">zone</strong></span> statements, + in which case it overrides the global <span><strong class="command">dialup</strong></span> + option. + </p> +<p> + If the zone is a master zone, then the server will send out a + NOTIFY + request to all the slaves (default). This should trigger the + zone serial + number check in the slave (providing it supports NOTIFY) + allowing the slave + to verify the zone while the connection is active. + The set of servers to which NOTIFY is sent can be controlled + by + <span><strong class="command">notify</strong></span> and <span><strong class="command">also-notify</strong></span>. + </p> +<p> + If the + zone is a slave or stub zone, then the server will suppress + the regular + "zone up to date" (refresh) queries and only perform them + when the + <span><strong class="command">heartbeat-interval</strong></span> expires in + addition to sending + NOTIFY requests. + </p> +<p> + Finer control can be achieved by using + <strong class="userinput"><code>notify</code></strong> which only sends NOTIFY + messages, + <strong class="userinput"><code>notify-passive</code></strong> which sends NOTIFY + messages and + suppresses the normal refresh queries, <strong class="userinput"><code>refresh</code></strong> + which suppresses normal refresh processing and sends refresh + queries + when the <span><strong class="command">heartbeat-interval</strong></span> + expires, and + <strong class="userinput"><code>passive</code></strong> which just disables normal + refresh + processing. + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + dialup mode + </p> + </td> +<td> + <p> + normal refresh + </p> + </td> +<td> + <p> + heart-beat refresh + </p> + </td> +<td> + <p> + heart-beat notify + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">no</strong></span> (default)</p> + </td> +<td> + <p> + yes + </p> + </td> +<td> + <p> + no + </p> + </td> +<td> + <p> + no + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">yes</strong></span></p> + </td> +<td> + <p> + no + </p> + </td> +<td> + <p> + yes + </p> + </td> +<td> + <p> + yes + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">notify</strong></span></p> + </td> +<td> + <p> + yes + </p> + </td> +<td> + <p> + no + </p> + </td> +<td> + <p> + yes + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">refresh</strong></span></p> + </td> +<td> + <p> + no + </p> + </td> +<td> + <p> + yes + </p> + </td> +<td> + <p> + no + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">passive</strong></span></p> + </td> +<td> + <p> + no + </p> + </td> +<td> + <p> + no + </p> + </td> +<td> + <p> + no + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">notify-passive</strong></span></p> + </td> +<td> + <p> + no + </p> + </td> +<td> + <p> + no + </p> + </td> +<td> + <p> + yes + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + Note that normal NOTIFY processing is not affected by + <span><strong class="command">dialup</strong></span>. + </p> +</dd> +<dt><span class="term"><span><strong class="command">fake-iquery</strong></span></span></dt> +<dd><p> + In <acronym class="acronym">BIND</acronym> 8, this option + enabled simulating the obsolete DNS query type + IQUERY. <acronym class="acronym">BIND</acronym> 9 never does + IQUERY simulation. + </p></dd> +<dt><span class="term"><span><strong class="command">fetch-glue</strong></span></span></dt> +<dd><p> + This option is obsolete. + In BIND 8, <strong class="userinput"><code>fetch-glue yes</code></strong> + caused the server to attempt to fetch glue resource records + it + didn't have when constructing the additional + data section of a response. This is now considered a bad + idea + and BIND 9 never does it. + </p></dd> +<dt><span class="term"><span><strong class="command">flush-zones-on-shutdown</strong></span></span></dt> +<dd><p> + When the nameserver exits due receiving SIGTERM, + flush or do not flush any pending zone writes. The default + is + <span><strong class="command">flush-zones-on-shutdown</strong></span> <strong class="userinput"><code>no</code></strong>. + </p></dd> +<dt><span class="term"><span><strong class="command">has-old-clients</strong></span></span></dt> +<dd><p> + This option was incorrectly implemented + in <acronym class="acronym">BIND</acronym> 8, and is ignored by <acronym class="acronym">BIND</acronym> 9. + To achieve the intended effect + of + <span><strong class="command">has-old-clients</strong></span> <strong class="userinput"><code>yes</code></strong>, specify + the two separate options <span><strong class="command">auth-nxdomain</strong></span> <strong class="userinput"><code>yes</code></strong> + and <span><strong class="command">rfc2308-type1</strong></span> <strong class="userinput"><code>no</code></strong> instead. + </p></dd> +<dt><span class="term"><span><strong class="command">host-statistics</strong></span></span></dt> +<dd><p> + In BIND 8, this enables keeping of + statistics for every host that the name server interacts + with. + Not implemented in BIND 9. + </p></dd> +<dt><span class="term"><span><strong class="command">maintain-ixfr-base</strong></span></span></dt> +<dd><p> + <span class="emphasis"><em>This option is obsolete</em></span>. + It was used in <acronym class="acronym">BIND</acronym> 8 to + determine whether a transaction log was + kept for Incremental Zone Transfer. <acronym class="acronym">BIND</acronym> 9 maintains a transaction + log whenever possible. If you need to disable outgoing + incremental zone + transfers, use <span><strong class="command">provide-ixfr</strong></span> <strong class="userinput"><code>no</code></strong>. + </p></dd> +<dt><span class="term"><span><strong class="command">minimal-responses</strong></span></span></dt> +<dd><p> + If <strong class="userinput"><code>yes</code></strong>, then when generating + responses the server will only add records to the authority + and additional data sections when they are required (e.g. + delegations, negative responses). This may improve the + performance of the server. + The default is <strong class="userinput"><code>no</code></strong>. + </p></dd> +<dt><span class="term"><span><strong class="command">multiple-cnames</strong></span></span></dt> +<dd><p> + This option was used in <acronym class="acronym">BIND</acronym> 8 to allow + a domain name to have multiple CNAME records in violation of + the DNS standards. <acronym class="acronym">BIND</acronym> 9.2 onwards + always strictly enforces the CNAME rules both in master + files and dynamic updates. + </p></dd> +<dt><span class="term"><span><strong class="command">notify</strong></span></span></dt> +<dd> +<p> + If <strong class="userinput"><code>yes</code></strong> (the default), + DNS NOTIFY messages are sent when a zone the server is + authoritative for + changes, see <a href="Bv9ARM.ch04.html#notify" title="Notify">the section called “Notify”</a>. The messages are + sent to the + servers listed in the zone's NS records (except the master + server identified + in the SOA MNAME field), and to any servers listed in the + <span><strong class="command">also-notify</strong></span> option. + </p> +<p> + If <strong class="userinput"><code>master-only</code></strong>, notifies are only + sent + for master zones. + If <strong class="userinput"><code>explicit</code></strong>, notifies are sent only + to + servers explicitly listed using <span><strong class="command">also-notify</strong></span>. + If <strong class="userinput"><code>no</code></strong>, no notifies are sent. + </p> +<p> + The <span><strong class="command">notify</strong></span> option may also be + specified in the <span><strong class="command">zone</strong></span> + statement, + in which case it overrides the <span><strong class="command">options notify</strong></span> statement. + It would only be necessary to turn off this option if it + caused slaves + to crash. + </p> +</dd> +<dt><span class="term"><span><strong class="command">recursion</strong></span></span></dt> +<dd><p> + If <strong class="userinput"><code>yes</code></strong>, and a + DNS query requests recursion, then the server will attempt + to do + all the work required to answer the query. If recursion is + off + and the server does not already know the answer, it will + return a + referral response. The default is + <strong class="userinput"><code>yes</code></strong>. + Note that setting <span><strong class="command">recursion no</strong></span> does not prevent + clients from getting data from the server's cache; it only + prevents new data from being cached as an effect of client + queries. + Caching may still occur as an effect the server's internal + operation, such as NOTIFY address lookups. + See also <span><strong class="command">fetch-glue</strong></span> above. + </p></dd> +<dt><span class="term"><span><strong class="command">rfc2308-type1</strong></span></span></dt> +<dd> +<p> + Setting this to <strong class="userinput"><code>yes</code></strong> will + cause the server to send NS records along with the SOA + record for negative + answers. The default is <strong class="userinput"><code>no</code></strong>. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + Not yet implemented in <acronym class="acronym">BIND</acronym> + 9. + </p> +</div> +</dd> +<dt><span class="term"><span><strong class="command">use-id-pool</strong></span></span></dt> +<dd><p> + <span class="emphasis"><em>This option is obsolete</em></span>. + <acronym class="acronym">BIND</acronym> 9 always allocates query + IDs from a pool. + </p></dd> +<dt><span class="term"><span><strong class="command">zone-statistics</strong></span></span></dt> +<dd><p> + If <strong class="userinput"><code>yes</code></strong>, the server will collect + statistical data on all zones (unless specifically turned + off + on a per-zone basis by specifying <span><strong class="command">zone-statistics no</strong></span> + in the <span><strong class="command">zone</strong></span> statement). + These statistics may be accessed + using <span><strong class="command">rndc stats</strong></span>, which will + dump them to the file listed + in the <span><strong class="command">statistics-file</strong></span>. See + also <a href="Bv9ARM.ch06.html#statsfile" title="The Statistics File">the section called “The Statistics File”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">use-ixfr</strong></span></span></dt> +<dd><p> + <span class="emphasis"><em>This option is obsolete</em></span>. + If you need to disable IXFR to a particular server or + servers, see + the information on the <span><strong class="command">provide-ixfr</strong></span> option + in <a href="Bv9ARM.ch06.html#server_statement_definition_and_usage" title="server Statement Definition and + Usage">the section called “<span><strong class="command">server</strong></span> Statement Definition and + Usage”</a>. + See also + <a href="Bv9ARM.ch04.html#incremental_zone_transfers" title="Incremental Zone Transfers (IXFR)">the section called “Incremental Zone Transfers (IXFR)”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">provide-ixfr</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">provide-ixfr</strong></span> in + <a href="Bv9ARM.ch06.html#server_statement_definition_and_usage" title="server Statement Definition and + Usage">the section called “<span><strong class="command">server</strong></span> Statement Definition and + Usage”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">request-ixfr</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">request-ixfr</strong></span> in + <a href="Bv9ARM.ch06.html#server_statement_definition_and_usage" title="server Statement Definition and + Usage">the section called “<span><strong class="command">server</strong></span> Statement Definition and + Usage”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">treat-cr-as-space</strong></span></span></dt> +<dd><p> + This option was used in <acronym class="acronym">BIND</acronym> + 8 to make + the server treat carriage return ("<span><strong class="command">\r</strong></span>") characters the same way + as a space or tab character, + to facilitate loading of zone files on a UNIX system that + were generated + on an NT or DOS machine. In <acronym class="acronym">BIND</acronym> 9, both UNIX "<span><strong class="command">\n</strong></span>" + and NT/DOS "<span><strong class="command">\r\n</strong></span>" newlines + are always accepted, + and the option is ignored. + </p></dd> +<dt> +<span class="term"><span><strong class="command">additional-from-auth</strong></span>, </span><span class="term"><span><strong class="command">additional-from-cache</strong></span></span> +</dt> +<dd> +<p> + These options control the behavior of an authoritative + server when + answering queries which have additional data, or when + following CNAME + and DNAME chains. + </p> +<p> + When both of these options are set to <strong class="userinput"><code>yes</code></strong> + (the default) and a + query is being answered from authoritative data (a zone + configured into the server), the additional data section of + the + reply will be filled in using data from other authoritative + zones + and from the cache. In some situations this is undesirable, + such + as when there is concern over the correctness of the cache, + or + in servers where slave zones may be added and modified by + untrusted third parties. Also, avoiding + the search for this additional data will speed up server + operations + at the possible expense of additional queries to resolve + what would + otherwise be provided in the additional section. + </p> +<p> + For example, if a query asks for an MX record for host <code class="literal">foo.example.com</code>, + and the record found is "<code class="literal">MX 10 mail.example.net</code>", normally the address + records (A and AAAA) for <code class="literal">mail.example.net</code> will be provided as well, + if known, even though they are not in the example.com zone. + Setting these options to <span><strong class="command">no</strong></span> + disables this behavior and makes + the server only search for additional data in the zone it + answers from. + </p> +<p> + These options are intended for use in authoritative-only + servers, or in authoritative-only views. Attempts to set + them to <span><strong class="command">no</strong></span> without also + specifying + <span><strong class="command">recursion no</strong></span> will cause the + server to + ignore the options and log a warning message. + </p> +<p> + Specifying <span><strong class="command">additional-from-cache no</strong></span> actually + disables the use of the cache not only for additional data + lookups + but also when looking up the answer. This is usually the + desired + behavior in an authoritative-only server where the + correctness of + the cached data is an issue. + </p> +<p> + When a name server is non-recursively queried for a name + that is not + below the apex of any served zone, it normally answers with + an + "upwards referral" to the root servers or the servers of + some other + known parent of the query name. Since the data in an + upwards referral + comes from the cache, the server will not be able to provide + upwards + referrals when <span><strong class="command">additional-from-cache no</strong></span> + has been specified. Instead, it will respond to such + queries + with REFUSED. This should not cause any problems since + upwards referrals are not required for the resolution + process. + </p> +</dd> +<dt><span class="term"><span><strong class="command">match-mapped-addresses</strong></span></span></dt> +<dd><p> + If <strong class="userinput"><code>yes</code></strong>, then an + IPv4-mapped IPv6 address will match any address match + list entries that match the corresponding IPv4 address. + Enabling this option is sometimes useful on IPv6-enabled + Linux + systems, to work around a kernel quirk that causes IPv4 + TCP connections such as zone transfers to be accepted + on an IPv6 socket using mapped addresses, causing + address match lists designed for IPv4 to fail to match. + The use of this option for any other purpose is discouraged. + </p></dd> +<dt><span class="term"><span><strong class="command">ixfr-from-differences</strong></span></span></dt> +<dd> +<p> + When <strong class="userinput"><code>yes</code></strong> and the server loads a new version of a master + zone from its zone file or receives a new version of a slave + file by a non-incremental zone transfer, it will compare + the new version to the previous one and calculate a set + of differences. The differences are then logged in the + zone's journal file such that the changes can be transmitted + to downstream slaves as an incremental zone transfer. + </p> +<p> + By allowing incremental zone transfers to be used for + non-dynamic zones, this option saves bandwidth at the + expense of increased CPU and memory consumption at the + master. + In particular, if the new version of a zone is completely + different from the previous one, the set of differences + will be of a size comparable to the combined size of the + old and new zone version, and the server will need to + temporarily allocate memory to hold this complete + difference set. + </p> +<p><span><strong class="command">ixfr-from-differences</strong></span> + also accepts <span><strong class="command">master</strong></span> and + <span><strong class="command">slave</strong></span> at the view and options + levels which causes + <span><strong class="command">ixfr-from-differences</strong></span> to apply to + all <span><strong class="command">master</strong></span> or + <span><strong class="command">slave</strong></span> zones respectively. + </p> +</dd> +<dt><span class="term"><span><strong class="command">multi-master</strong></span></span></dt> +<dd><p> + This should be set when you have multiple masters for a zone + and the + addresses refer to different machines. If <strong class="userinput"><code>yes</code></strong>, named will + not log + when the serial number on the master is less than what named + currently + has. The default is <strong class="userinput"><code>no</code></strong>. + </p></dd> +<dt><span class="term"><span><strong class="command">dnssec-enable</strong></span></span></dt> +<dd><p> + Enable DNSSEC support in named. Unless set to <strong class="userinput"><code>yes</code></strong>, + named behaves as if it does not support DNSSEC. + The default is <strong class="userinput"><code>yes</code></strong>. + </p></dd> +<dt><span class="term"><span><strong class="command">dnssec-validation</strong></span></span></dt> +<dd><p> + Enable DNSSEC validation in named. + Note <span><strong class="command">dnssec-enable</strong></span> also needs to be + set to <strong class="userinput"><code>yes</code></strong> to be effective. + The default is <strong class="userinput"><code>no</code></strong>. + </p></dd> +<dt><span class="term"><span><strong class="command">dnssec-accept-expired</strong></span></span></dt> +<dd><p> + Accept expired signatures when verifying DNSSEC signatures. + The default is <strong class="userinput"><code>no</code></strong>. + Setting this option to "yes" leaves named vulnerable to replay attacks. + </p></dd> +<dt><span class="term"><span><strong class="command">querylog</strong></span></span></dt> +<dd><p> + Specify whether query logging should be started when named + starts. + If <span><strong class="command">querylog</strong></span> is not specified, + then the query logging + is determined by the presence of the logging category <span><strong class="command">queries</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-names</strong></span></span></dt> +<dd> +<p> + This option is used to restrict the character set and syntax + of + certain domain names in master files and/or DNS responses + received + from the network. The default varies according to usage + area. For + <span><strong class="command">master</strong></span> zones the default is <span><strong class="command">fail</strong></span>. + For <span><strong class="command">slave</strong></span> zones the default + is <span><strong class="command">warn</strong></span>. + For answers received from the network (<span><strong class="command">response</strong></span>) + the default is <span><strong class="command">ignore</strong></span>. + </p> +<p> + The rules for legal hostnames and mail domains are derived + from RFC 952 and RFC 821 as modified by RFC 1123. + </p> +<p><span><strong class="command">check-names</strong></span> + applies to the owner names of A, AAA and MX records. + It also applies to the domain names in the RDATA of NS, SOA + and MX records. + It also applies to the RDATA of PTR records where the owner + name indicated that it is a reverse lookup of a hostname + (the owner name ends in IN-ADDR.ARPA, IP6.ARPA, or IP6.INT). + </p> +</dd> +<dt><span class="term"><span><strong class="command">check-mx</strong></span></span></dt> +<dd><p> + Check whether the MX record appears to refer to a IP address. + The default is to <span><strong class="command">warn</strong></span>. Other possible + values are <span><strong class="command">fail</strong></span> and + <span><strong class="command">ignore</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-wildcard</strong></span></span></dt> +<dd><p> + This option is used to check for non-terminal wildcards. + The use of non-terminal wildcards is almost always as a + result of a failure + to understand the wildcard matching algorithm (RFC 1034). + This option + affects master zones. The default (<span><strong class="command">yes</strong></span>) is to check + for non-terminal wildcards and issue a warning. + </p></dd> +<dt><span class="term"><span><strong class="command">check-integrity</strong></span></span></dt> +<dd><p> + Perform post load zone integrity checks on master + zones. This checks that MX and SRV records refer + to address (A or AAAA) records and that glue + address records exist for delegated zones. For + MX and SRV records only in-zone hostnames are + checked (for out-of-zone hostnames use named-checkzone). + For NS records only names below top of zone are + checked (for out-of-zone names and glue consistency + checks use named-checkzone). The default is + <span><strong class="command">yes</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-mx-cname</strong></span></span></dt> +<dd><p> + If <span><strong class="command">check-integrity</strong></span> is set then + fail, warn or ignore MX records that refer + to CNAMES. The default is to <span><strong class="command">warn</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-srv-cname</strong></span></span></dt> +<dd><p> + If <span><strong class="command">check-integrity</strong></span> is set then + fail, warn or ignore SRV records that refer + to CNAMES. The default is to <span><strong class="command">warn</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-sibling</strong></span></span></dt> +<dd><p> + When performing integrity checks, also check that + sibling glue exists. The default is <span><strong class="command">yes</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">zero-no-soa-ttl</strong></span></span></dt> +<dd><p> + When returning authoritative negative responses to + SOA queries set the TTL of the SOA recored returned in + the authority section to zero. + The default is <span><strong class="command">yes</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">zero-no-soa-ttl-cache</strong></span></span></dt> +<dd><p> + When caching a negative response to a SOA query + set the TTL to zero. + The default is <span><strong class="command">no</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">update-check-ksk</strong></span></span></dt> +<dd><p> + When regenerating the RRSIGs following a UPDATE + request to a secure zone, check the KSK flag on + the DNSKEY RR to determine if this key should be + used to generate the RRSIG. This flag is ignored + if there are not DNSKEY RRs both with and without + a KSK. + The default is <span><strong class="command">yes</strong></span>. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2580536"></a>Forwarding</h4></div></div></div> +<p> + The forwarding facility can be used to create a large site-wide + cache on a few servers, reducing traffic over links to external + name servers. It can also be used to allow queries by servers that + do not have direct access to the Internet, but wish to look up + exterior + names anyway. Forwarding occurs only on those queries for which + the server is not authoritative and does not have the answer in + its cache. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">forward</strong></span></span></dt> +<dd><p> + This option is only meaningful if the + forwarders list is not empty. A value of <code class="varname">first</code>, + the default, causes the server to query the forwarders + first — and + if that doesn't answer the question, the server will then + look for + the answer itself. If <code class="varname">only</code> is + specified, the + server will only query the forwarders. + </p></dd> +<dt><span class="term"><span><strong class="command">forwarders</strong></span></span></dt> +<dd><p> + Specifies the IP addresses to be used + for forwarding. The default is the empty list (no + forwarding). + </p></dd> +</dl></div> +<p> + Forwarding can also be configured on a per-domain basis, allowing + for the global forwarding options to be overridden in a variety + of ways. You can set particular domains to use different + forwarders, + or have a different <span><strong class="command">forward only/first</strong></span> behavior, + or not forward at all, see <a href="Bv9ARM.ch06.html#zone_statement_grammar" title="zone + Statement Grammar">the section called “<span><strong class="command">zone</strong></span> + Statement Grammar”</a>. + </p> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2580595"></a>Dual-stack Servers</h4></div></div></div> +<p> + Dual-stack servers are used as servers of last resort to work + around + problems in reachability due the lack of support for either IPv4 + or IPv6 + on the host machine. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">dual-stack-servers</strong></span></span></dt> +<dd><p> + Specifies host names or addresses of machines with access to + both IPv4 and IPv6 transports. If a hostname is used, the + server must be able + to resolve the name using only the transport it has. If the + machine is dual + stacked, then the <span><strong class="command">dual-stack-servers</strong></span> have no effect unless + access to a transport has been disabled on the command line + (e.g. <span><strong class="command">named -4</strong></span>). + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="access_control"></a>Access Control</h4></div></div></div> +<p> + Access to the server can be restricted based on the IP address + of the requesting system. See <a href="Bv9ARM.ch06.html#address_match_lists" title="Address Match Lists">the section called “Address Match Lists”</a> for + details on how to specify IP address lists. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">allow-notify</strong></span></span></dt> +<dd><p> + Specifies which hosts are allowed to + notify this server, a slave, of zone changes in addition + to the zone masters. + <span><strong class="command">allow-notify</strong></span> may also be + specified in the + <span><strong class="command">zone</strong></span> statement, in which case + it overrides the + <span><strong class="command">options allow-notify</strong></span> + statement. It is only meaningful + for a slave zone. If not specified, the default is to + process notify messages + only from a zone's master. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-query</strong></span></span></dt> +<dd> +<p> + Specifies which hosts are allowed to ask ordinary + DNS questions. <span><strong class="command">allow-query</strong></span> may + also be specified in the <span><strong class="command">zone</strong></span> + statement, in which case it overrides the + <span><strong class="command">options allow-query</strong></span> statement. + If not specified, the default is to allow queries + from all hosts. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + <span><strong class="command">allow-query-cache</strong></span> is now + used to specify access to the cache. + </p> +</div> +</dd> +<dt><span class="term"><span><strong class="command">allow-query-cache</strong></span></span></dt> +<dd><p> + Specifies which hosts are allowed to get answers + from the cache. If <span><strong class="command">allow-query-cache</strong></span> + is not set then <span><strong class="command">allow-recursion</strong></span> + is used if set, otherwise <span><strong class="command">allow-query</strong></span> + is used if set, otherwise the default + (<span><strong class="command">localnets;</strong></span> + <span><strong class="command">localhost;</strong></span>) is used. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-recursion</strong></span></span></dt> +<dd><p> + Specifies which hosts are allowed to make recursive + queries through this server. If + <span><strong class="command">allow-recursion</strong></span> is not set + then <span><strong class="command">allow-query-cache</strong></span> is + used if set, otherwise <span><strong class="command">allow-query</strong></span> + is used if set, otherwise the default + (<span><strong class="command">localnets;</strong></span> + <span><strong class="command">localhost;</strong></span>) is used. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-update</strong></span></span></dt> +<dd><p> + Specifies which hosts are allowed to + submit Dynamic DNS updates for master zones. The default is + to deny + updates from all hosts. Note that allowing updates based + on the requestor's IP address is insecure; see + <a href="Bv9ARM.ch07.html#dynamic_update_security" title="Dynamic Update Security">the section called “Dynamic Update Security”</a> for details. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-update-forwarding</strong></span></span></dt> +<dd> +<p> + Specifies which hosts are allowed to + submit Dynamic DNS updates to slave zones to be forwarded to + the + master. The default is <strong class="userinput"><code>{ none; }</code></strong>, + which + means that no update forwarding will be performed. To + enable + update forwarding, specify + <strong class="userinput"><code>allow-update-forwarding { any; };</code></strong>. + Specifying values other than <strong class="userinput"><code>{ none; }</code></strong> or + <strong class="userinput"><code>{ any; }</code></strong> is usually + counterproductive, since + the responsibility for update access control should rest + with the + master server, not the slaves. + </p> +<p> + Note that enabling the update forwarding feature on a slave + server + may expose master servers relying on insecure IP address + based + access control to attacks; see <a href="Bv9ARM.ch07.html#dynamic_update_security" title="Dynamic Update Security">the section called “Dynamic Update Security”</a> + for more details. + </p> +</dd> +<dt><span class="term"><span><strong class="command">allow-v6-synthesis</strong></span></span></dt> +<dd><p> + This option was introduced for the smooth transition from + AAAA + to A6 and from "nibble labels" to binary labels. + However, since both A6 and binary labels were then + deprecated, + this option was also deprecated. + It is now ignored with some warning messages. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-transfer</strong></span></span></dt> +<dd><p> + Specifies which hosts are allowed to + receive zone transfers from the server. <span><strong class="command">allow-transfer</strong></span> may + also be specified in the <span><strong class="command">zone</strong></span> + statement, in which + case it overrides the <span><strong class="command">options allow-transfer</strong></span> statement. + If not specified, the default is to allow transfers to all + hosts. + </p></dd> +<dt><span class="term"><span><strong class="command">blackhole</strong></span></span></dt> +<dd><p> + Specifies a list of addresses that the + server will not accept queries from or use to resolve a + query. Queries + from these addresses will not be responded to. The default + is <strong class="userinput"><code>none</code></strong>. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2581153"></a>Interfaces</h4></div></div></div> +<p> + The interfaces and ports that the server will answer queries + from may be specified using the <span><strong class="command">listen-on</strong></span> option. <span><strong class="command">listen-on</strong></span> takes + an optional port, and an <code class="varname">address_match_list</code>. + The server will listen on all interfaces allowed by the address + match list. If a port is not specified, port 53 will be used. + </p> +<p> + Multiple <span><strong class="command">listen-on</strong></span> statements are + allowed. + For example, + </p> +<pre class="programlisting">listen-on { 5.6.7.8; }; +listen-on port 1234 { !1.2.3.4; 1.2/16; }; +</pre> +<p> + will enable the name server on port 53 for the IP address + 5.6.7.8, and on port 1234 of an address on the machine in net + 1.2 that is not 1.2.3.4. + </p> +<p> + If no <span><strong class="command">listen-on</strong></span> is specified, the + server will listen on port 53 on all interfaces. + </p> +<p> + The <span><strong class="command">listen-on-v6</strong></span> option is used to + specify the interfaces and the ports on which the server will + listen + for incoming queries sent using IPv6. + </p> +<p> + When </p> +<pre class="programlisting">{ any; }</pre> +<p> is + specified + as the <code class="varname">address_match_list</code> for the + <span><strong class="command">listen-on-v6</strong></span> option, + the server does not bind a separate socket to each IPv6 interface + address as it does for IPv4 if the operating system has enough API + support for IPv6 (specifically if it conforms to RFC 3493 and RFC + 3542). + Instead, it listens on the IPv6 wildcard address. + If the system only has incomplete API support for IPv6, however, + the behavior is the same as that for IPv4. + </p> +<p> + A list of particular IPv6 addresses can also be specified, in + which case + the server listens on a separate socket for each specified + address, + regardless of whether the desired API is supported by the system. + </p> +<p> + Multiple <span><strong class="command">listen-on-v6</strong></span> options can + be used. + For example, + </p> +<pre class="programlisting">listen-on-v6 { any; }; +listen-on-v6 port 1234 { !2001:db8::/32; any; }; +</pre> +<p> + will enable the name server on port 53 for any IPv6 addresses + (with a single wildcard socket), + and on port 1234 of IPv6 addresses that is not in the prefix + 2001:db8::/32 (with separate sockets for each matched address.) + </p> +<p> + To make the server not listen on any IPv6 address, use + </p> +<pre class="programlisting">listen-on-v6 { none; }; +</pre> +<p> + If no <span><strong class="command">listen-on-v6</strong></span> option is + specified, + the server will not listen on any IPv6 address. + </p> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2581241"></a>Query Address</h4></div></div></div> +<p> + If the server doesn't know the answer to a question, it will + query other name servers. <span><strong class="command">query-source</strong></span> specifies + the address and port used for such queries. For queries sent over + IPv6, there is a separate <span><strong class="command">query-source-v6</strong></span> option. + If <span><strong class="command">address</strong></span> is <span><strong class="command">*</strong></span> (asterisk) or is omitted, + a wildcard IP address (<span><strong class="command">INADDR_ANY</strong></span>) + will be used. + If <span><strong class="command">port</strong></span> is <span><strong class="command">*</strong></span> or is omitted, + a random unprivileged port will be used. The <span><strong class="command">avoid-v4-udp-ports</strong></span> + and <span><strong class="command">avoid-v6-udp-ports</strong></span> options can be used + to prevent named + from selecting certain ports. The defaults are: + </p> +<pre class="programlisting">query-source address * port *; +query-source-v6 address * port *; +</pre> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + The address specified in the <span><strong class="command">query-source</strong></span> option + is used for both UDP and TCP queries, but the port applies only + to + UDP queries. TCP queries always use a random + unprivileged port. + </p> +</div> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + Solaris 2.5.1 and earlier does not support setting the source + address for TCP sockets. + </p> +</div> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + See also <span><strong class="command">transfer-source</strong></span> and + <span><strong class="command">notify-source</strong></span>. + </p> +</div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="zone_transfers"></a>Zone Transfers</h4></div></div></div> +<p> + <acronym class="acronym">BIND</acronym> has mechanisms in place to + facilitate zone transfers + and set limits on the amount of load that transfers place on the + system. The following options apply to zone transfers. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">also-notify</strong></span></span></dt> +<dd><p> + Defines a global list of IP addresses of name servers + that are also sent NOTIFY messages whenever a fresh copy of + the + zone is loaded, in addition to the servers listed in the + zone's NS records. + This helps to ensure that copies of the zones will + quickly converge on stealth servers. If an <span><strong class="command">also-notify</strong></span> list + is given in a <span><strong class="command">zone</strong></span> statement, + it will override + the <span><strong class="command">options also-notify</strong></span> + statement. When a <span><strong class="command">zone notify</strong></span> + statement + is set to <span><strong class="command">no</strong></span>, the IP + addresses in the global <span><strong class="command">also-notify</strong></span> list will + not be sent NOTIFY messages for that zone. The default is + the empty + list (no global notification list). + </p></dd> +<dt><span class="term"><span><strong class="command">max-transfer-time-in</strong></span></span></dt> +<dd><p> + Inbound zone transfers running longer than + this many minutes will be terminated. The default is 120 + minutes + (2 hours). The maximum value is 28 days (40320 minutes). + </p></dd> +<dt><span class="term"><span><strong class="command">max-transfer-idle-in</strong></span></span></dt> +<dd><p> + Inbound zone transfers making no progress + in this many minutes will be terminated. The default is 60 + minutes + (1 hour). The maximum value is 28 days (40320 minutes). + </p></dd> +<dt><span class="term"><span><strong class="command">max-transfer-time-out</strong></span></span></dt> +<dd><p> + Outbound zone transfers running longer than + this many minutes will be terminated. The default is 120 + minutes + (2 hours). The maximum value is 28 days (40320 minutes). + </p></dd> +<dt><span class="term"><span><strong class="command">max-transfer-idle-out</strong></span></span></dt> +<dd><p> + Outbound zone transfers making no progress + in this many minutes will be terminated. The default is 60 + minutes (1 + hour). The maximum value is 28 days (40320 minutes). + </p></dd> +<dt><span class="term"><span><strong class="command">serial-query-rate</strong></span></span></dt> +<dd><p> + Slave servers will periodically query master servers + to find out if zone serial numbers have changed. Each such + query uses + a minute amount of the slave server's network bandwidth. To + limit the + amount of bandwidth used, BIND 9 limits the rate at which + queries are + sent. The value of the <span><strong class="command">serial-query-rate</strong></span> option, + an integer, is the maximum number of queries sent per + second. + The default is 20. + </p></dd> +<dt><span class="term"><span><strong class="command">serial-queries</strong></span></span></dt> +<dd><p> + In BIND 8, the <span><strong class="command">serial-queries</strong></span> + option + set the maximum number of concurrent serial number queries + allowed to be outstanding at any given time. + BIND 9 does not limit the number of outstanding + serial queries and ignores the <span><strong class="command">serial-queries</strong></span> option. + Instead, it limits the rate at which the queries are sent + as defined using the <span><strong class="command">serial-query-rate</strong></span> option. + </p></dd> +<dt><span class="term"><span><strong class="command">transfer-format</strong></span></span></dt> +<dd><p> + Zone transfers can be sent using two different formats, + <span><strong class="command">one-answer</strong></span> and + <span><strong class="command">many-answers</strong></span>. + The <span><strong class="command">transfer-format</strong></span> option is used + on the master server to determine which format it sends. + <span><strong class="command">one-answer</strong></span> uses one DNS message per + resource record transferred. + <span><strong class="command">many-answers</strong></span> packs as many resource + records as possible into a message. + <span><strong class="command">many-answers</strong></span> is more efficient, but is + only supported by relatively new slave servers, + such as <acronym class="acronym">BIND</acronym> 9, <acronym class="acronym">BIND</acronym> + 8.x and <acronym class="acronym">BIND</acronym> 4.9.5 onwards. + The <span><strong class="command">many-answers</strong></span> format is also supported by + recent Microsoft Windows nameservers. + The default is <span><strong class="command">many-answers</strong></span>. + <span><strong class="command">transfer-format</strong></span> may be overridden on a + per-server basis by using the <span><strong class="command">server</strong></span> + statement. + </p></dd> +<dt><span class="term"><span><strong class="command">transfers-in</strong></span></span></dt> +<dd><p> + The maximum number of inbound zone transfers + that can be running concurrently. The default value is <code class="literal">10</code>. + Increasing <span><strong class="command">transfers-in</strong></span> may + speed up the convergence + of slave zones, but it also may increase the load on the + local system. + </p></dd> +<dt><span class="term"><span><strong class="command">transfers-out</strong></span></span></dt> +<dd><p> + The maximum number of outbound zone transfers + that can be running concurrently. Zone transfer requests in + excess + of the limit will be refused. The default value is <code class="literal">10</code>. + </p></dd> +<dt><span class="term"><span><strong class="command">transfers-per-ns</strong></span></span></dt> +<dd><p> + The maximum number of inbound zone transfers + that can be concurrently transferring from a given remote + name server. + The default value is <code class="literal">2</code>. + Increasing <span><strong class="command">transfers-per-ns</strong></span> + may + speed up the convergence of slave zones, but it also may + increase + the load on the remote name server. <span><strong class="command">transfers-per-ns</strong></span> may + be overridden on a per-server basis by using the <span><strong class="command">transfers</strong></span> phrase + of the <span><strong class="command">server</strong></span> statement. + </p></dd> +<dt><span class="term"><span><strong class="command">transfer-source</strong></span></span></dt> +<dd> +<p><span><strong class="command">transfer-source</strong></span> + determines which local address will be bound to IPv4 + TCP connections used to fetch zones transferred + inbound by the server. It also determines the + source IPv4 address, and optionally the UDP port, + used for the refresh queries and forwarded dynamic + updates. If not set, it defaults to a system + controlled value which will usually be the address + of the interface "closest to" the remote end. This + address must appear in the remote end's + <span><strong class="command">allow-transfer</strong></span> option for the + zone being transferred, if one is specified. This + statement sets the + <span><strong class="command">transfer-source</strong></span> for all zones, + but can be overridden on a per-view or per-zone + basis by including a + <span><strong class="command">transfer-source</strong></span> statement within + the <span><strong class="command">view</strong></span> or + <span><strong class="command">zone</strong></span> block in the configuration + file. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + Solaris 2.5.1 and earlier does not support setting the + source address for TCP sockets. + </p> +</div> +</dd> +<dt><span class="term"><span><strong class="command">transfer-source-v6</strong></span></span></dt> +<dd><p> + The same as <span><strong class="command">transfer-source</strong></span>, + except zone transfers are performed using IPv6. + </p></dd> +<dt><span class="term"><span><strong class="command">alt-transfer-source</strong></span></span></dt> +<dd> +<p> + An alternate transfer source if the one listed in + <span><strong class="command">transfer-source</strong></span> fails and + <span><strong class="command">use-alt-transfer-source</strong></span> is + set. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> + If you do not wish the alternate transfer source + to be used, you should set + <span><strong class="command">use-alt-transfer-source</strong></span> + appropriately and you should not depend upon + getting a answer back to the first refresh + query. + </div> +</dd> +<dt><span class="term"><span><strong class="command">alt-transfer-source-v6</strong></span></span></dt> +<dd><p> + An alternate transfer source if the one listed in + <span><strong class="command">transfer-source-v6</strong></span> fails and + <span><strong class="command">use-alt-transfer-source</strong></span> is + set. + </p></dd> +<dt><span class="term"><span><strong class="command">use-alt-transfer-source</strong></span></span></dt> +<dd><p> + Use the alternate transfer sources or not. If views are + specified this defaults to <span><strong class="command">no</strong></span> + otherwise it defaults to + <span><strong class="command">yes</strong></span> (for BIND 8 + compatibility). + </p></dd> +<dt><span class="term"><span><strong class="command">notify-source</strong></span></span></dt> +<dd> +<p><span><strong class="command">notify-source</strong></span> + determines which local source address, and + optionally UDP port, will be used to send NOTIFY + messages. This address must appear in the slave + server's <span><strong class="command">masters</strong></span> zone clause or + in an <span><strong class="command">allow-notify</strong></span> clause. This + statement sets the <span><strong class="command">notify-source</strong></span> + for all zones, but can be overridden on a per-zone or + per-view basis by including a + <span><strong class="command">notify-source</strong></span> statement within + the <span><strong class="command">zone</strong></span> or + <span><strong class="command">view</strong></span> block in the configuration + file. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + Solaris 2.5.1 and earlier does not support setting the + source address for TCP sockets. + </p> +</div> +</dd> +<dt><span class="term"><span><strong class="command">notify-source-v6</strong></span></span></dt> +<dd><p> + Like <span><strong class="command">notify-source</strong></span>, + but applies to notify messages sent to IPv6 addresses. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2581988"></a>Bad UDP Port Lists</h4></div></div></div> +<p><span><strong class="command">avoid-v4-udp-ports</strong></span> + and <span><strong class="command">avoid-v6-udp-ports</strong></span> specify a list + of IPv4 and IPv6 UDP ports that will not be used as system + assigned source ports for UDP sockets. These lists + prevent named from choosing as its random source port a + port that is blocked by your firewall. If a query went + out with such a source port, the answer would not get by + the firewall and the name server would have to query + again. + </p> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2582003"></a>Operating System Resource Limits</h4></div></div></div> +<p> + The server's usage of many system resources can be limited. + Scaled values are allowed when specifying resource limits. For + example, <span><strong class="command">1G</strong></span> can be used instead of + <span><strong class="command">1073741824</strong></span> to specify a limit of + one + gigabyte. <span><strong class="command">unlimited</strong></span> requests + unlimited use, or the + maximum available amount. <span><strong class="command">default</strong></span> + uses the limit + that was in force when the server was started. See the description + of <span><strong class="command">size_spec</strong></span> in <a href="Bv9ARM.ch06.html#configuration_file_elements" title="Configuration File Elements">the section called “Configuration File Elements”</a>. + </p> +<p> + The following options set operating system resource limits for + the name server process. Some operating systems don't support + some or + any of the limits. On such systems, a warning will be issued if + the + unsupported limit is used. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">coresize</strong></span></span></dt> +<dd><p> + The maximum size of a core dump. The default + is <code class="literal">default</code>. + </p></dd> +<dt><span class="term"><span><strong class="command">datasize</strong></span></span></dt> +<dd><p> + The maximum amount of data memory the server + may use. The default is <code class="literal">default</code>. + This is a hard limit on server memory usage. + If the server attempts to allocate memory in excess of this + limit, the allocation will fail, which may in turn leave + the server unable to perform DNS service. Therefore, + this option is rarely useful as a way of limiting the + amount of memory used by the server, but it can be used + to raise an operating system data size limit that is + too small by default. If you wish to limit the amount + of memory used by the server, use the + <span><strong class="command">max-cache-size</strong></span> and + <span><strong class="command">recursive-clients</strong></span> + options instead. + </p></dd> +<dt><span class="term"><span><strong class="command">files</strong></span></span></dt> +<dd><p> + The maximum number of files the server + may have open concurrently. The default is <code class="literal">unlimited</code>. + </p></dd> +<dt><span class="term"><span><strong class="command">stacksize</strong></span></span></dt> +<dd><p> + The maximum amount of stack memory the server + may use. The default is <code class="literal">default</code>. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2582186"></a>Server Resource Limits</h4></div></div></div> +<p> + The following options set limits on the server's + resource consumption that are enforced internally by the + server rather than the operating system. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">max-ixfr-log-size</strong></span></span></dt> +<dd><p> + This option is obsolete; it is accepted + and ignored for BIND 8 compatibility. The option + <span><strong class="command">max-journal-size</strong></span> performs a + similar function in BIND 9. + </p></dd> +<dt><span class="term"><span><strong class="command">max-journal-size</strong></span></span></dt> +<dd><p> + Sets a maximum size for each journal file + (see <a href="Bv9ARM.ch04.html#journal" title="The journal file">the section called “The journal file”</a>). When the journal file + approaches + the specified size, some of the oldest transactions in the + journal + will be automatically removed. The default is + <code class="literal">unlimited</code>. + </p></dd> +<dt><span class="term"><span><strong class="command">host-statistics-max</strong></span></span></dt> +<dd><p> + In BIND 8, specifies the maximum number of host statistics + entries to be kept. + Not implemented in BIND 9. + </p></dd> +<dt><span class="term"><span><strong class="command">recursive-clients</strong></span></span></dt> +<dd><p> + The maximum number of simultaneous recursive lookups + the server will perform on behalf of clients. The default + is + <code class="literal">1000</code>. Because each recursing + client uses a fair + bit of memory, on the order of 20 kilobytes, the value of + the + <span><strong class="command">recursive-clients</strong></span> option may + have to be decreased + on hosts with limited memory. + </p></dd> +<dt><span class="term"><span><strong class="command">tcp-clients</strong></span></span></dt> +<dd><p> + The maximum number of simultaneous client TCP + connections that the server will accept. + The default is <code class="literal">100</code>. + </p></dd> +<dt><span class="term"><span><strong class="command">max-cache-size</strong></span></span></dt> +<dd><p> + The maximum amount of memory to use for the + server's cache, in bytes. When the amount of data in the + cache + reaches this limit, the server will cause records to expire + prematurely so that the limit is not exceeded. In a server + with + multiple views, the limit applies separately to the cache of + each + view. The default is <code class="literal">unlimited</code>, meaning that + records are purged from the cache only when their TTLs + expire. + </p></dd> +<dt><span class="term"><span><strong class="command">tcp-listen-queue</strong></span></span></dt> +<dd><p> + The listen queue depth. The default and minimum is 3. + If the kernel supports the accept filter "dataready" this + also controls how + many TCP connections that will be queued in kernel space + waiting for + some data before being passed to accept. Values less than 3 + will be + silently raised. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2582320"></a>Periodic Task Intervals</h4></div></div></div> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">cleaning-interval</strong></span></span></dt> +<dd><p> + The server will remove expired resource records + from the cache every <span><strong class="command">cleaning-interval</strong></span> minutes. + The default is 60 minutes. The maximum value is 28 days + (40320 minutes). + If set to 0, no periodic cleaning will occur. + </p></dd> +<dt><span class="term"><span><strong class="command">heartbeat-interval</strong></span></span></dt> +<dd><p> + The server will perform zone maintenance tasks + for all zones marked as <span><strong class="command">dialup</strong></span> whenever this + interval expires. The default is 60 minutes. Reasonable + values are up + to 1 day (1440 minutes). The maximum value is 28 days + (40320 minutes). + If set to 0, no zone maintenance for these zones will occur. + </p></dd> +<dt><span class="term"><span><strong class="command">interface-interval</strong></span></span></dt> +<dd><p> + The server will scan the network interface list + every <span><strong class="command">interface-interval</strong></span> + minutes. The default + is 60 minutes. The maximum value is 28 days (40320 minutes). + If set to 0, interface scanning will only occur when + the configuration file is loaded. After the scan, the + server will + begin listening for queries on any newly discovered + interfaces (provided they are allowed by the + <span><strong class="command">listen-on</strong></span> configuration), and + will + stop listening on interfaces that have gone away. + </p></dd> +<dt><span class="term"><span><strong class="command">statistics-interval</strong></span></span></dt> +<dd> +<p> + Name server statistics will be logged + every <span><strong class="command">statistics-interval</strong></span> + minutes. The default is + 60. The maximum value is 28 days (40320 minutes). + If set to 0, no statistics will be logged. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + Not yet implemented in + <acronym class="acronym">BIND</acronym> 9. + </p> +</div> +</dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="topology"></a>Topology</h4></div></div></div> +<p> + All other things being equal, when the server chooses a name + server + to query from a list of name servers, it prefers the one that is + topologically closest to itself. The <span><strong class="command">topology</strong></span> statement + takes an <span><strong class="command">address_match_list</strong></span> and + interprets it + in a special way. Each top-level list element is assigned a + distance. + Non-negated elements get a distance based on their position in the + list, where the closer the match is to the start of the list, the + shorter the distance is between it and the server. A negated match + will be assigned the maximum distance from the server. If there + is no match, the address will get a distance which is further than + any non-negated list element, and closer than any negated element. + For example, + </p> +<pre class="programlisting">topology { + 10/8; + !1.2.3/24; + { 1.2/16; 3/8; }; +};</pre> +<p> + will prefer servers on network 10 the most, followed by hosts + on network 1.2.0.0 (netmask 255.255.0.0) and network 3, with the + exception of hosts on network 1.2.3 (netmask 255.255.255.0), which + is preferred least of all. + </p> +<p> + The default topology is + </p> +<pre class="programlisting"> topology { localhost; localnets; }; +</pre> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + The <span><strong class="command">topology</strong></span> option + is not implemented in <acronym class="acronym">BIND</acronym> 9. + </p> +</div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="the_sortlist_statement"></a>The <span><strong class="command">sortlist</strong></span> Statement</h4></div></div></div> +<p> + The response to a DNS query may consist of multiple resource + records (RRs) forming a resource records set (RRset). + The name server will normally return the + RRs within the RRset in an indeterminate order + (but see the <span><strong class="command">rrset-order</strong></span> + statement in <a href="Bv9ARM.ch06.html#rrset_ordering" title="RRset Ordering">the section called “RRset Ordering”</a>). + The client resolver code should rearrange the RRs as appropriate, + that is, using any addresses on the local net in preference to + other addresses. + However, not all resolvers can do this or are correctly + configured. + When a client is using a local server, the sorting can be performed + in the server, based on the client's address. This only requires + configuring the name servers, not all the clients. + </p> +<p> + The <span><strong class="command">sortlist</strong></span> statement (see below) + takes + an <span><strong class="command">address_match_list</strong></span> and + interprets it even + more specifically than the <span><strong class="command">topology</strong></span> + statement + does (<a href="Bv9ARM.ch06.html#topology" title="Topology">the section called “Topology”</a>). + Each top level statement in the <span><strong class="command">sortlist</strong></span> must + itself be an explicit <span><strong class="command">address_match_list</strong></span> with + one or two elements. The first element (which may be an IP + address, + an IP prefix, an ACL name or a nested <span><strong class="command">address_match_list</strong></span>) + of each top level list is checked against the source address of + the query until a match is found. + </p> +<p> + Once the source address of the query has been matched, if + the top level statement contains only one element, the actual + primitive + element that matched the source address is used to select the + address + in the response to move to the beginning of the response. If the + statement is a list of two elements, then the second element is + treated the same as the <span><strong class="command">address_match_list</strong></span> in + a <span><strong class="command">topology</strong></span> statement. Each top + level element + is assigned a distance and the address in the response with the + minimum + distance is moved to the beginning of the response. + </p> +<p> + In the following example, any queries received from any of + the addresses of the host itself will get responses preferring + addresses + on any of the locally connected networks. Next most preferred are + addresses + on the 192.168.1/24 network, and after that either the + 192.168.2/24 + or + 192.168.3/24 network with no preference shown between these two + networks. Queries received from a host on the 192.168.1/24 network + will prefer other addresses on that network to the 192.168.2/24 + and + 192.168.3/24 networks. Queries received from a host on the + 192.168.4/24 + or the 192.168.5/24 network will only prefer other addresses on + their directly connected networks. + </p> +<pre class="programlisting">sortlist { + { localhost; // IF the local host + { localnets; // THEN first fit on the + 192.168.1/24; // following nets + { 192.168.2/24; 192.168.3/24; }; }; }; + { 192.168.1/24; // IF on class C 192.168.1 + { 192.168.1/24; // THEN use .1, or .2 or .3 + { 192.168.2/24; 192.168.3/24; }; }; }; + { 192.168.2/24; // IF on class C 192.168.2 + { 192.168.2/24; // THEN use .2, or .1 or .3 + { 192.168.1/24; 192.168.3/24; }; }; }; + { 192.168.3/24; // IF on class C 192.168.3 + { 192.168.3/24; // THEN use .3, or .1 or .2 + { 192.168.1/24; 192.168.2/24; }; }; }; + { { 192.168.4/24; 192.168.5/24; }; // if .4 or .5, prefer that net + }; +};</pre> +<p> + The following example will give reasonable behavior for the + local host and hosts on directly connected networks. It is similar + to the behavior of the address sort in <acronym class="acronym">BIND</acronym> 4.9.x. Responses sent + to queries from the local host will favor any of the directly + connected + networks. Responses sent to queries from any other hosts on a + directly + connected network will prefer addresses on that same network. + Responses + to other queries will not be sorted. + </p> +<pre class="programlisting">sortlist { + { localhost; localnets; }; + { localnets; }; +}; +</pre> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="rrset_ordering"></a>RRset Ordering</h4></div></div></div> +<p> + When multiple records are returned in an answer it may be + useful to configure the order of the records placed into the + response. + The <span><strong class="command">rrset-order</strong></span> statement permits + configuration + of the ordering of the records in a multiple record response. + See also the <span><strong class="command">sortlist</strong></span> statement, + <a href="Bv9ARM.ch06.html#the_sortlist_statement" title="The sortlist Statement">the section called “The <span><strong class="command">sortlist</strong></span> Statement”</a>. + </p> +<p> + An <span><strong class="command">order_spec</strong></span> is defined as + follows: + </p> +<p> + [<span class="optional">class <em class="replaceable"><code>class_name</code></em></span>] + [<span class="optional">type <em class="replaceable"><code>type_name</code></em></span>] + [<span class="optional">name <em class="replaceable"><code>"domain_name"</code></em></span>] + order <em class="replaceable"><code>ordering</code></em> + </p> +<p> + If no class is specified, the default is <span><strong class="command">ANY</strong></span>. + If no type is specified, the default is <span><strong class="command">ANY</strong></span>. + If no name is specified, the default is "<span><strong class="command">*</strong></span>" (asterisk). + </p> +<p> + The legal values for <span><strong class="command">ordering</strong></span> are: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p><span><strong class="command">fixed</strong></span></p> + </td> +<td> + <p> + Records are returned in the order they + are defined in the zone file. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">random</strong></span></p> + </td> +<td> + <p> + Records are returned in some random order. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">cyclic</strong></span></p> + </td> +<td> + <p> + Records are returned in a round-robin + order. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + For example: + </p> +<pre class="programlisting">rrset-order { + class IN type A name "host.example.com" order random; + order cyclic; +}; +</pre> +<p> + will cause any responses for type A records in class IN that + have "<code class="literal">host.example.com</code>" as a + suffix, to always be returned + in random order. All other records are returned in cyclic order. + </p> +<p> + If multiple <span><strong class="command">rrset-order</strong></span> statements + appear, + they are not combined — the last one applies. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + The <span><strong class="command">rrset-order</strong></span> statement + is not yet fully implemented in <acronym class="acronym">BIND</acronym> 9. + BIND 9 currently does not fully support "fixed" ordering. + </p> +</div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="tuning"></a>Tuning</h4></div></div></div> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">lame-ttl</strong></span></span></dt> +<dd><p> + Sets the number of seconds to cache a + lame server indication. 0 disables caching. (This is + <span class="bold"><strong>NOT</strong></span> recommended.) + The default is <code class="literal">600</code> (10 minutes) and the + maximum value is + <code class="literal">1800</code> (30 minutes). + </p></dd> +<dt><span class="term"><span><strong class="command">max-ncache-ttl</strong></span></span></dt> +<dd><p> + To reduce network traffic and increase performance, + the server stores negative answers. <span><strong class="command">max-ncache-ttl</strong></span> is + used to set a maximum retention time for these answers in + the server + in seconds. The default + <span><strong class="command">max-ncache-ttl</strong></span> is <code class="literal">10800</code> seconds (3 hours). + <span><strong class="command">max-ncache-ttl</strong></span> cannot exceed + 7 days and will + be silently truncated to 7 days if set to a greater value. + </p></dd> +<dt><span class="term"><span><strong class="command">max-cache-ttl</strong></span></span></dt> +<dd><p> + Sets the maximum time for which the server will + cache ordinary (positive) answers. The default is + one week (7 days). + </p></dd> +<dt><span class="term"><span><strong class="command">min-roots</strong></span></span></dt> +<dd> +<p> + The minimum number of root servers that + is required for a request for the root servers to be + accepted. The default + is <strong class="userinput"><code>2</code></strong>. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + Not implemented in <acronym class="acronym">BIND</acronym> 9. + </p> +</div> +</dd> +<dt><span class="term"><span><strong class="command">sig-validity-interval</strong></span></span></dt> +<dd><p> + Specifies the number of days into the + future when DNSSEC signatures automatically generated as a + result + of dynamic updates (<a href="Bv9ARM.ch04.html#dynamic_update" title="Dynamic Update">the section called “Dynamic Update”</a>) + will expire. The default is <code class="literal">30</code> days. + The maximum value is 10 years (3660 days). The signature + inception time is unconditionally set to one hour before the + current time + to allow for a limited amount of clock skew. + </p></dd> +<dt> +<span class="term"><span><strong class="command">min-refresh-time</strong></span>, </span><span class="term"><span><strong class="command">max-refresh-time</strong></span>, </span><span class="term"><span><strong class="command">min-retry-time</strong></span>, </span><span class="term"><span><strong class="command">max-retry-time</strong></span></span> +</dt> +<dd> +<p> + These options control the server's behavior on refreshing a + zone + (querying for SOA changes) or retrying failed transfers. + Usually the SOA values for the zone are used, but these + values + are set by the master, giving slave server administrators + little + control over their contents. + </p> +<p> + These options allow the administrator to set a minimum and + maximum + refresh and retry time either per-zone, per-view, or + globally. + These options are valid for slave and stub zones, + and clamp the SOA refresh and retry times to the specified + values. + </p> +</dd> +<dt><span class="term"><span><strong class="command">edns-udp-size</strong></span></span></dt> +<dd><p> + Sets the advertised EDNS UDP buffer size in bytes. Valid + values are 512 to 4096 (values outside this range + will be silently adjusted). The default value is + 4096. The usual reason for setting edns-udp-size to + a non-default value is to get UDP answers to pass + through broken firewalls that block fragmented + packets and/or block UDP packets that are greater + than 512 bytes. + </p></dd> +<dt><span class="term"><span><strong class="command">max-udp-size</strong></span></span></dt> +<dd><p> + Sets the maximum EDNS UDP message size named will + send in bytes. Valid values are 512 to 4096 (values outside + this range will be silently adjusted). The default + value is 4096. The usual reason for setting + max-udp-size to a non-default value is to get UDP + answers to pass through broken firewalls that + block fragmented packets and/or block UDP packets + that are greater than 512 bytes. + This is independent of the advertised receive + buffer (<span><strong class="command">edns-udp-size</strong></span>). + </p></dd> +<dt><span class="term"><span><strong class="command">masterfile-format</strong></span></span></dt> +<dd><p>Specifies + the file format of zone files (see + <a href="Bv9ARM.ch06.html#zonefile_format" title="Additional File Formats">the section called “Additional File Formats”</a>). + The default value is <code class="constant">text</code>, which is the + standard textual representation. Files in other formats + than <code class="constant">text</code> are typically expected + to be generated by the <span><strong class="command">named-compilezone</strong></span> tool. + Note that when a zone file in a different format than + <code class="constant">text</code> is loaded, <span><strong class="command">named</strong></span> + may omit some of the checks which would be performed for a + file in the <code class="constant">text</code> format. In particular, + <span><strong class="command">check-names</strong></span> checks do not apply + for the <code class="constant">raw</code> format. This means + a zone file in the <code class="constant">raw</code> format + must be generated with the same check level as that + specified in the <span><strong class="command">named</strong></span> configuration + file. This statement sets the + <span><strong class="command">masterfile-format</strong></span> for all zones, + but can be overridden on a per-zone or per-view basis + by including a <span><strong class="command">masterfile-format</strong></span> + statement within the <span><strong class="command">zone</strong></span> or + <span><strong class="command">view</strong></span> block in the configuration + file. + </p></dd> +<dt> +<span class="term"><span><strong class="command">clients-per-query</strong></span>, </span><span class="term"><span><strong class="command">max-clients-per-query</strong></span></span> +</dt> +<dd> +<p>These set the + initial value (minimum) and maximum number of recursive + simultanious clients for any given query + (<qname,qtype,qclass>) that the server will accept + before dropping additional clients. named will attempt to + self tune this value and changes will be logged. The + default values are 10 and 100. + </p> +<p> + This value should reflect how many queries come in for + a given name in the time it takes to resolve that name. + If the number of queries exceed this value, named will + assume that it is dealing with a non-responsive zone + and will drop additional queries. If it gets a response + after dropping queries, it will raise the estimate. The + estimate will then be lowered in 20 minutes if it has + remained unchanged. + </p> +<p> + If <span><strong class="command">clients-per-query</strong></span> is set to zero, + then there is no limit on the number of clients per query + and no queries will be dropped. + </p> +<p> + If <span><strong class="command">max-clients-per-query</strong></span> is set to zero, + then there is no upper bound other than imposed by + <span><strong class="command">recursive-clients</strong></span>. + </p> +</dd> +<dt><span class="term"><span><strong class="command">notify-delay</strong></span></span></dt> +<dd><p> + The delay, in seconds, between sending sets of notify + messages for a zone. The default is zero. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="builtin"></a>Built-in server information zones</h4></div></div></div> +<p> + The server provides some helpful diagnostic information + through a number of built-in zones under the + pseudo-top-level-domain <code class="literal">bind</code> in the + <span><strong class="command">CHAOS</strong></span> class. These zones are part + of a + built-in view (see <a href="Bv9ARM.ch06.html#view_statement_grammar" title="view Statement Grammar">the section called “<span><strong class="command">view</strong></span> Statement Grammar”</a>) of + class + <span><strong class="command">CHAOS</strong></span> which is separate from the + default view of + class <span><strong class="command">IN</strong></span>; therefore, any global + server options + such as <span><strong class="command">allow-query</strong></span> do not apply + the these zones. + If you feel the need to disable these zones, use the options + below, or hide the built-in <span><strong class="command">CHAOS</strong></span> + view by + defining an explicit view of class <span><strong class="command">CHAOS</strong></span> + that matches all clients. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">version</strong></span></span></dt> +<dd><p> + The version the server should report + via a query of the name <code class="literal">version.bind</code> + with type <span><strong class="command">TXT</strong></span>, class <span><strong class="command">CHAOS</strong></span>. + The default is the real version number of this server. + Specifying <span><strong class="command">version none</strong></span> + disables processing of the queries. + </p></dd> +<dt><span class="term"><span><strong class="command">hostname</strong></span></span></dt> +<dd><p> + The hostname the server should report via a query of + the name <code class="filename">hostname.bind</code> + with type <span><strong class="command">TXT</strong></span>, class <span><strong class="command">CHAOS</strong></span>. + This defaults to the hostname of the machine hosting the + name server as + found by the gethostname() function. The primary purpose of such queries + is to + identify which of a group of anycast servers is actually + answering your queries. Specifying <span><strong class="command">hostname none;</strong></span> + disables processing of the queries. + </p></dd> +<dt><span class="term"><span><strong class="command">server-id</strong></span></span></dt> +<dd><p> + The ID of the server should report via a query of + the name <code class="filename">ID.SERVER</code> + with type <span><strong class="command">TXT</strong></span>, class <span><strong class="command">CHAOS</strong></span>. + The primary purpose of such queries is to + identify which of a group of anycast servers is actually + answering your queries. Specifying <span><strong class="command">server-id none;</strong></span> + disables processing of the queries. + Specifying <span><strong class="command">server-id hostname;</strong></span> will cause named to + use the hostname as found by the gethostname() function. + The default <span><strong class="command">server-id</strong></span> is <span><strong class="command">none</strong></span>. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="empty"></a>Built-in Empty Zones</h4></div></div></div> +<p> + Named has some built-in empty zones (SOA and NS records only). + These are for zones that should normally be answered locally + and which queries should not be sent to the Internet's root + servers. The official servers which cover these namespaces + return NXDOMAIN responses to these queries. In particular, + these cover the reverse namespace for addresses from RFC 1918 and + RFC 3330. They also include the reverse namespace for IPv6 local + address (locally assigned), IPv6 link local addresses, the IPv6 + loopback address and the IPv6 unknown addresss. + </p> +<p> + Named will attempt to determine if a built in zone already exists + or is active (covered by a forward-only forwarding declaration) + and will not not create a empty zone in that case. + </p> +<p> + The current list of empty zones is: + </p> +<div class="itemizedlist"><ul type="disc"> +<li>10.IN-ADDR.ARPA</li> +<li>127.IN-ADDR.ARPA</li> +<li>254.169.IN-ADDR.ARPA</li> +<li>16.172.IN-ADDR.ARPA</li> +<li>17.172.IN-ADDR.ARPA</li> +<li>18.172.IN-ADDR.ARPA</li> +<li>19.172.IN-ADDR.ARPA</li> +<li>20.172.IN-ADDR.ARPA</li> +<li>21.172.IN-ADDR.ARPA</li> +<li>22.172.IN-ADDR.ARPA</li> +<li>23.172.IN-ADDR.ARPA</li> +<li>24.172.IN-ADDR.ARPA</li> +<li>25.172.IN-ADDR.ARPA</li> +<li>26.172.IN-ADDR.ARPA</li> +<li>27.172.IN-ADDR.ARPA</li> +<li>28.172.IN-ADDR.ARPA</li> +<li>29.172.IN-ADDR.ARPA</li> +<li>30.172.IN-ADDR.ARPA</li> +<li>31.172.IN-ADDR.ARPA</li> +<li>168.192.IN-ADDR.ARPA</li> +<li>2.0.192.IN-ADDR.ARPA</li> +<li>0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP6.ARPA</li> +<li>1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP6.ARPA</li> +<li>D.F.IP6.ARPA</li> +<li>8.E.F.IP6.ARPA</li> +<li>9.E.F.IP6.ARPA</li> +<li>A.E.F.IP6.ARPA</li> +<li>B.E.F.IP6.ARPA</li> +</ul></div> +<p> + </p> +<p> + Empty zones are settable at the view level and only apply to + views of class IN. Disabled empty zones are only inherited + from options if there are no disabled empty zones specified + at the view level. To override the options list of disabled + zones, you can disable the root zone at the view level, for example: +</p> +<pre class="programlisting"> + disable-empty-zone "."; +</pre> +<p> + </p> +<p> + If you are using the address ranges covered here, you should + already have reverse zones covering the addresses you use. + In practice this appears to not be the case with many queries + being made to the infrastructure servers for names in these + spaces. So many in fact that sacrificial servers were needed + to be deployed to channel the query load away from the + infrastructure servers. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> + The real parent servers for these zones should disable all + empty zone under the parent zone they serve. For the real + root servers, this is all built in empty zones. This will + enable them to return referrals to deeper in the tree. + </div> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">empty-server</strong></span></span></dt> +<dd><p> + Specify what server name will appear in the returned + SOA record for empty zones. If none is specified, then + the zone's name will be used. + </p></dd> +<dt><span class="term"><span><strong class="command">empty-contact</strong></span></span></dt> +<dd><p> + Specify what contact name will appear in the returned + SOA record for empty zones. If none is specified, then + "." will be used. + </p></dd> +<dt><span class="term"><span><strong class="command">empty-zones-enable</strong></span></span></dt> +<dd><p> + Enable or disable all empty zones. By default they + are enabled. + </p></dd> +<dt><span class="term"><span><strong class="command">disable-empty-zone</strong></span></span></dt> +<dd><p> + Disable individual empty zones. By default none are + disabled. This option can be specified multiple times. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="statsfile"></a>The Statistics File</h4></div></div></div> +<p> + The statistics file generated by <acronym class="acronym">BIND</acronym> 9 + is similar, but not identical, to that + generated by <acronym class="acronym">BIND</acronym> 8. + </p> +<p> + The statistics dump begins with a line, like: + </p> +<p> + <span><strong class="command">+++ Statistics Dump +++ (973798949)</strong></span> + </p> +<p> + The number in parentheses is a standard + Unix-style timestamp, measured as seconds since January 1, 1970. + Following + that line are a series of lines containing a counter type, the + value of the + counter, optionally a zone name, and optionally a view name. + The lines without view and zone listed are global statistics for + the entire server. + Lines with a zone and view name for the given view and zone (the + view name is + omitted for the default view). + </p> +<p> + The statistics dump ends with the line where the + number is identical to the number in the beginning line; for example: + </p> +<p> + <span><strong class="command">--- Statistics Dump --- (973798949)</strong></span> + </p> +<p> + The following statistics counters are maintained: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p><span><strong class="command">success</strong></span></p> + </td> +<td> + <p> + The number of + successful queries made to the server or zone. A + successful query + is defined as query which returns a NOERROR response + with at least + one answer RR. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">referral</strong></span></p> + </td> +<td> + <p> + The number of queries which resulted + in referral responses. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">nxrrset</strong></span></p> + </td> +<td> + <p> + The number of queries which resulted in + NOERROR responses with no data. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">nxdomain</strong></span></p> + </td> +<td> + <p> + The number + of queries which resulted in NXDOMAIN responses. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">failure</strong></span></p> + </td> +<td> + <p> + The number of queries which resulted in a + failure response other than those above. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">recursion</strong></span></p> + </td> +<td> + <p> + The number of queries which caused the server + to perform recursion in order to find the final answer. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">duplicate</strong></span></p> + </td> +<td> + <p> + The number of queries which the server attempted to + recurse but discover a existing query with the same + IP address, port, query id, name, type and class + already being processed. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">dropped</strong></span></p> + </td> +<td> + <p> + The number of queries for which the server + discovered a excessive number of existing + recursive queries for the same name, type and + class and were subsequently dropped. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + Each query received by the server will cause exactly one of + <span><strong class="command">success</strong></span>, + <span><strong class="command">referral</strong></span>, + <span><strong class="command">nxrrset</strong></span>, + <span><strong class="command">nxdomain</strong></span>, or + <span><strong class="command">failure</strong></span> + to be incremented, and may additionally cause the + <span><strong class="command">recursion</strong></span> counter to be + incremented. + </p> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="acache"></a>Additional Section Caching</h4></div></div></div> +<p> + The additional section cache, also called <span><strong class="command">acache</strong></span>, + is an internal cache to improve the response performance of BIND 9. + When additional section caching is enabled, BIND 9 will + cache an internal short-cut to the additional section content for + each answer RR. + Note that <span><strong class="command">acache</strong></span> is an internal caching + mechanism of BIND 9, and is not related to the DNS caching + server function. + </p> +<p> + Additional section caching does not change the + response content (except the RRsets ordering of the additional + section, see below), but can improve the response performance + significantly. + It is particularly effective when BIND 9 acts as an authoritative + server for a zone that has many delegations with many glue RRs. + </p> +<p> + In order to obtain the maximum performance improvement + from additional section caching, setting + <span><strong class="command">additional-from-cache</strong></span> + to <span><strong class="command">no</strong></span> is recommended, since the current + implementation of <span><strong class="command">acache</strong></span> + does not short-cut of additional section information from the + DNS cache data. + </p> +<p> + One obvious disadvantage of <span><strong class="command">acache</strong></span> is + that it requires much more + memory for the internal cached data. + Thus, if the response performance does not matter and memory + consumption is much more critical, the + <span><strong class="command">acache</strong></span> mechanism can be + disabled by setting <span><strong class="command">acache-enable</strong></span> to + <span><strong class="command">no</strong></span>. + It is also possible to specify the upper limit of memory + consumption + for acache by using <span><strong class="command">max-acache-size</strong></span>. + </p> +<p> + Additional section caching also has a minor effect on the + RRset ordering in the additional section. + Without <span><strong class="command">acache</strong></span>, + <span><strong class="command">cyclic</strong></span> order is effective for the additional + section as well as the answer and authority sections. + However, additional section caching fixes the ordering when it + first caches an RRset for the additional section, and the same + ordering will be kept in succeeding responses, regardless of the + setting of <span><strong class="command">rrset-order</strong></span>. + The effect of this should be minor, however, since an + RRset in the additional section + typically only contains a small number of RRs (and in many cases + it only contains a single RR), in which case the + ordering does not matter much. + </p> +<p> + The following is a summary of options related to + <span><strong class="command">acache</strong></span>. + </p> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">acache-enable</strong></span></span></dt> +<dd><p> + If <span><strong class="command">yes</strong></span>, additional section caching is + enabled. The default value is <span><strong class="command">no</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">acache-cleaning-interval</strong></span></span></dt> +<dd><p> + The server will remove stale cache entries, based on an LRU + based + algorithm, every <span><strong class="command">acache-cleaning-interval</strong></span> minutes. + The default is 60 minutes. + If set to 0, no periodic cleaning will occur. + </p></dd> +<dt><span class="term"><span><strong class="command">max-acache-size</strong></span></span></dt> +<dd><p> + The maximum amount of memory in bytes to use for the server's acache. + When the amount of data in the acache reaches this limit, + the server + will clean more aggressively so that the limit is not + exceeded. + In a server with multiple views, the limit applies + separately to the + acache of each view. + The default is <code class="literal">unlimited</code>, + meaning that + entries are purged from the acache only at the + periodic cleaning time. + </p></dd> +</dl></div> +</div> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="server_statement_grammar"></a><span><strong class="command">server</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting">server <em class="replaceable"><code>ip_addr[/prefixlen]</code></em> { + [<span class="optional"> bogus <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> provide-ixfr <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> request-ixfr <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> edns <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> edns-udp-size <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-udp-size <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> transfers <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> transfer-format <em class="replaceable"><code>( one-answer | many-answers )</code></em> ; ]</span>] + [<span class="optional"> keys <em class="replaceable"><code>{ string ; [<span class="optional"> string ; [<span class="optional">...</span>]</span>] }</code></em> ; </span>] + [<span class="optional"> transfer-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> transfer-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> notify-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> notify-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> query-source [<span class="optional"> address ( <em class="replaceable"><code>ip_addr</code></em> | <em class="replaceable"><code>*</code></em> ) </span>] [<span class="optional"> port ( <em class="replaceable"><code>ip_port</code></em> | <em class="replaceable"><code>*</code></em> ) </span>]; </span>] + [<span class="optional"> query-source-v6 [<span class="optional"> address ( <em class="replaceable"><code>ip_addr</code></em> | <em class="replaceable"><code>*</code></em> ) </span>] [<span class="optional"> port ( <em class="replaceable"><code>ip_port</code></em> | <em class="replaceable"><code>*</code></em> ) </span>]; </span>] +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="server_statement_definition_and_usage"></a><span><strong class="command">server</strong></span> Statement Definition and + Usage</h3></div></div></div> +<p> + The <span><strong class="command">server</strong></span> statement defines + characteristics + to be associated with a remote name server. If a prefix length is + specified, then a range of servers is covered. Only the most + specific + server clause applies regardless of the order in + <code class="filename">named.conf</code>. + </p> +<p> + The <span><strong class="command">server</strong></span> statement can occur at + the top level of the + configuration file or inside a <span><strong class="command">view</strong></span> + statement. + If a <span><strong class="command">view</strong></span> statement contains + one or more <span><strong class="command">server</strong></span> statements, only + those + apply to the view and any top-level ones are ignored. + If a view contains no <span><strong class="command">server</strong></span> + statements, + any top-level <span><strong class="command">server</strong></span> statements are + used as + defaults. + </p> +<p> + If you discover that a remote server is giving out bad data, + marking it as bogus will prevent further queries to it. The + default + value of <span><strong class="command">bogus</strong></span> is <span><strong class="command">no</strong></span>. + </p> +<p> + The <span><strong class="command">provide-ixfr</strong></span> clause determines + whether + the local server, acting as master, will respond with an + incremental + zone transfer when the given remote server, a slave, requests it. + If set to <span><strong class="command">yes</strong></span>, incremental transfer + will be provided + whenever possible. If set to <span><strong class="command">no</strong></span>, + all transfers + to the remote server will be non-incremental. If not set, the + value + of the <span><strong class="command">provide-ixfr</strong></span> option in the + view or + global options block is used as a default. + </p> +<p> + The <span><strong class="command">request-ixfr</strong></span> clause determines + whether + the local server, acting as a slave, will request incremental zone + transfers from the given remote server, a master. If not set, the + value of the <span><strong class="command">request-ixfr</strong></span> option in + the view or + global options block is used as a default. + </p> +<p> + IXFR requests to servers that do not support IXFR will + automatically + fall back to AXFR. Therefore, there is no need to manually list + which servers support IXFR and which ones do not; the global + default + of <span><strong class="command">yes</strong></span> should always work. + The purpose of the <span><strong class="command">provide-ixfr</strong></span> and + <span><strong class="command">request-ixfr</strong></span> clauses is + to make it possible to disable the use of IXFR even when both + master + and slave claim to support it, for example if one of the servers + is buggy and crashes or corrupts data when IXFR is used. + </p> +<p> + The <span><strong class="command">edns</strong></span> clause determines whether + the local server will attempt to use EDNS when communicating + with the remote server. The default is <span><strong class="command">yes</strong></span>. + </p> +<p> + The <span><strong class="command">edns-udp-size</strong></span> option sets the EDNS UDP size + that is advertised by named when querying the remote server. + Valid values are 512 to 4096 bytes (values outside this range will be + silently adjusted). This option is useful when you wish to + advertises a different value to this server than the value you + advertise globally, for example, when there is a firewall at the + remote site that is blocking large replies. + </p> +<p> + The <span><strong class="command">max-udp-size</strong></span> option sets the + maximum EDNS UDP message size named will send. Valid + values are 512 to 4096 bytes (values outside this range will + be silently adjusted). This option is useful when you + know that there is a firewall that is blocking large + replies from named. + </p> +<p> + The server supports two zone transfer methods. The first, <span><strong class="command">one-answer</strong></span>, + uses one DNS message per resource record transferred. <span><strong class="command">many-answers</strong></span> packs + as many resource records as possible into a message. <span><strong class="command">many-answers</strong></span> is + more efficient, but is only known to be understood by <acronym class="acronym">BIND</acronym> 9, <acronym class="acronym">BIND</acronym> + 8.x, and patched versions of <acronym class="acronym">BIND</acronym> + 4.9.5. You can specify which method + to use for a server with the <span><strong class="command">transfer-format</strong></span> option. + If <span><strong class="command">transfer-format</strong></span> is not + specified, the <span><strong class="command">transfer-format</strong></span> + specified + by the <span><strong class="command">options</strong></span> statement will be + used. + </p> +<p><span><strong class="command">transfers</strong></span> + is used to limit the number of concurrent inbound zone + transfers from the specified server. If no + <span><strong class="command">transfers</strong></span> clause is specified, the + limit is set according to the + <span><strong class="command">transfers-per-ns</strong></span> option. + </p> +<p> + The <span><strong class="command">keys</strong></span> clause identifies a + <span><strong class="command">key_id</strong></span> defined by the <span><strong class="command">key</strong></span> statement, + to be used for transaction security (TSIG, <a href="Bv9ARM.ch04.html#tsig" title="TSIG">the section called “TSIG”</a>) + when talking to the remote server. + When a request is sent to the remote server, a request signature + will be generated using the key specified here and appended to the + message. A request originating from the remote server is not + required + to be signed by this key. + </p> +<p> + Although the grammar of the <span><strong class="command">keys</strong></span> + clause + allows for multiple keys, only a single key per server is + currently + supported. + </p> +<p> + The <span><strong class="command">transfer-source</strong></span> and + <span><strong class="command">transfer-source-v6</strong></span> clauses specify + the IPv4 and IPv6 source + address to be used for zone transfer with the remote server, + respectively. + For an IPv4 remote server, only <span><strong class="command">transfer-source</strong></span> can + be specified. + Similarly, for an IPv6 remote server, only + <span><strong class="command">transfer-source-v6</strong></span> can be + specified. + For more details, see the description of + <span><strong class="command">transfer-source</strong></span> and + <span><strong class="command">transfer-source-v6</strong></span> in + <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p> +<p> + The <span><strong class="command">notify-source</strong></span> and + <span><strong class="command">notify-source-v6</strong></span> clauses specify the + IPv4 and IPv6 source address to be used for notify + messages sent to remote servers, respectively. For an + IPv4 remote server, only <span><strong class="command">notify-source</strong></span> + can be specified. Similarly, for an IPv6 remote server, + only <span><strong class="command">notify-source-v6</strong></span> can be specified. + </p> +<p> + The <span><strong class="command">query-source</strong></span> and + <span><strong class="command">query-source-v6</strong></span> clauses specify the + IPv4 and IPv6 source address to be used for queries + sent to remote servers, respectively. For an IPv4 + remote server, only <span><strong class="command">query-source</strong></span> can + be specified. Similarly, for an IPv6 remote server, + only <span><strong class="command">query-source-v6</strong></span> can be specified. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2585361"></a><span><strong class="command">trusted-keys</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting">trusted-keys { + <em class="replaceable"><code>string</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>string</code></em> ; + [<span class="optional"> <em class="replaceable"><code>string</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>string</code></em> ; [<span class="optional">...</span>]</span>] +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2585410"></a><span><strong class="command">trusted-keys</strong></span> Statement Definition + and Usage</h3></div></div></div> +<p> + The <span><strong class="command">trusted-keys</strong></span> statement defines + DNSSEC security roots. DNSSEC is described in <a href="Bv9ARM.ch04.html#DNSSEC" title="DNSSEC">the section called “DNSSEC”</a>. A security root is defined when the + public key for a non-authoritative zone is known, but + cannot be securely obtained through DNS, either because + it is the DNS root zone or because its parent zone is + unsigned. Once a key has been configured as a trusted + key, it is treated as if it had been validated and + proven secure. The resolver attempts DNSSEC validation + on all DNS data in subdomains of a security root. + </p> +<p> + All keys (and corresponding zones) listed in + <span><strong class="command">trusted-keys</strong></span> are deemed to exist regardless + of what parent zones say. Similarly for all keys listed in + <span><strong class="command">trusted-keys</strong></span> only those keys are + used to validate the DNSKEY RRset. The parent's DS RRset + will not be used. + </p> +<p> + The <span><strong class="command">trusted-keys</strong></span> statement can contain + multiple key entries, each consisting of the key's + domain name, flags, protocol, algorithm, and the Base-64 + representation of the key data. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="view_statement_grammar"></a><span><strong class="command">view</strong></span> Statement Grammar</h3></div></div></div> +<pre class="programlisting">view <em class="replaceable"><code>view_name</code></em> + [<span class="optional"><em class="replaceable"><code>class</code></em></span>] { + match-clients { <em class="replaceable"><code>address_match_list</code></em> }; + match-destinations { <em class="replaceable"><code>address_match_list</code></em> }; + match-recursive-only <em class="replaceable"><code>yes_or_no</code></em> ; + [<span class="optional"> <em class="replaceable"><code>view_option</code></em>; ...</span>] + [<span class="optional"> <em class="replaceable"><code>zone_statement</code></em>; ...</span>] +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2585490"></a><span><strong class="command">view</strong></span> Statement Definition and Usage</h3></div></div></div> +<p> + The <span><strong class="command">view</strong></span> statement is a powerful + feature + of <acronym class="acronym">BIND</acronym> 9 that lets a name server + answer a DNS query differently + depending on who is asking. It is particularly useful for + implementing + split DNS setups without having to run multiple servers. + </p> +<p> + Each <span><strong class="command">view</strong></span> statement defines a view + of the + DNS namespace that will be seen by a subset of clients. A client + matches + a view if its source IP address matches the + <code class="varname">address_match_list</code> of the view's + <span><strong class="command">match-clients</strong></span> clause and its + destination IP address matches + the <code class="varname">address_match_list</code> of the + view's + <span><strong class="command">match-destinations</strong></span> clause. If not + specified, both + <span><strong class="command">match-clients</strong></span> and <span><strong class="command">match-destinations</strong></span> + default to matching all addresses. In addition to checking IP + addresses + <span><strong class="command">match-clients</strong></span> and <span><strong class="command">match-destinations</strong></span> + can also take <span><strong class="command">keys</strong></span> which provide an + mechanism for the + client to select the view. A view can also be specified + as <span><strong class="command">match-recursive-only</strong></span>, which + means that only recursive + requests from matching clients will match that view. + The order of the <span><strong class="command">view</strong></span> statements is + significant — + a client request will be resolved in the context of the first + <span><strong class="command">view</strong></span> that it matches. + </p> +<p> + Zones defined within a <span><strong class="command">view</strong></span> + statement will + be only be accessible to clients that match the <span><strong class="command">view</strong></span>. + By defining a zone of the same name in multiple views, different + zone data can be given to different clients, for example, + "internal" + and "external" clients in a split DNS setup. + </p> +<p> + Many of the options given in the <span><strong class="command">options</strong></span> statement + can also be used within a <span><strong class="command">view</strong></span> + statement, and then + apply only when resolving queries with that view. When no + view-specific + value is given, the value in the <span><strong class="command">options</strong></span> statement + is used as a default. Also, zone options can have default values + specified + in the <span><strong class="command">view</strong></span> statement; these + view-specific defaults + take precedence over those in the <span><strong class="command">options</strong></span> statement. + </p> +<p> + Views are class specific. If no class is given, class IN + is assumed. Note that all non-IN views must contain a hint zone, + since only the IN class has compiled-in default hints. + </p> +<p> + If there are no <span><strong class="command">view</strong></span> statements in + the config + file, a default view that matches any client is automatically + created + in class IN. Any <span><strong class="command">zone</strong></span> statements + specified on + the top level of the configuration file are considered to be part + of + this default view, and the <span><strong class="command">options</strong></span> + statement will + apply to the default view. If any explicit <span><strong class="command">view</strong></span> + statements are present, all <span><strong class="command">zone</strong></span> + statements must + occur inside <span><strong class="command">view</strong></span> statements. + </p> +<p> + Here is an example of a typical split DNS setup implemented + using <span><strong class="command">view</strong></span> statements: + </p> +<pre class="programlisting">view "internal" { + // This should match our internal networks. + match-clients { 10.0.0.0/8; }; + + // Provide recursive service to internal clients only. + recursion yes; + + // Provide a complete view of the example.com zone + // including addresses of internal hosts. + zone "example.com" { + type master; + file "example-internal.db"; + }; +}; + +view "external" { + // Match all clients not matched by the previous view. + match-clients { any; }; + + // Refuse recursive service to external clients. + recursion no; + + // Provide a restricted view of the example.com zone + // containing only publicly accessible hosts. + zone "example.com" { + type master; + file "example-external.db"; + }; +}; +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="zone_statement_grammar"></a><span><strong class="command">zone</strong></span> + Statement Grammar</h3></div></div></div> +<pre class="programlisting">zone <em class="replaceable"><code>zone_name</code></em> [<span class="optional"><em class="replaceable"><code>class</code></em></span>] { + type master; + [<span class="optional"> allow-query { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-transfer { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-update { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> update-policy { <em class="replaceable"><code>update_policy_rule</code></em> [<span class="optional">...</span>] }; </span>] + [<span class="optional"> also-notify { <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> check-names (<code class="constant">warn</code>|<code class="constant">fail</code>|<code class="constant">ignore</code>) ; </span>] + [<span class="optional"> check-mx (<code class="constant">warn</code>|<code class="constant">fail</code>|<code class="constant">ignore</code>) ; </span>] + [<span class="optional"> check-wildcard <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> check-integrity <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> dialup <em class="replaceable"><code>dialup_option</code></em> ; </span>] + [<span class="optional"> file <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> masterfile-format (<code class="constant">text</code>|<code class="constant">raw</code>) ; </span>] + [<span class="optional"> journal <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> forward (<code class="constant">only</code>|<code class="constant">first</code>) ; </span>] + [<span class="optional"> forwarders { [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> ixfr-base <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> ixfr-tmp-file <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> maintain-ixfr-base <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> max-ixfr-log-size <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-transfer-idle-out <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-transfer-time-out <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> notify <em class="replaceable"><code>yes_or_no</code></em> | <em class="replaceable"><code>explicit</code></em> | <em class="replaceable"><code>master-only</code></em> ; </span>] + [<span class="optional"> notify-delay <em class="replaceable"><code>seconds</code></em> ; </span>] + [<span class="optional"> pubkey <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> notify-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> notify-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> zone-statistics <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> sig-validity-interval <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> database <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> min-refresh-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-refresh-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> min-retry-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-retry-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> key-directory <em class="replaceable"><code>path_name</code></em>; </span>] + [<span class="optional"> zero-no-soa-ttl <em class="replaceable"><code>yes_or_no</code></em> ; </span>] +}; + +zone <em class="replaceable"><code>zone_name</code></em> [<span class="optional"><em class="replaceable"><code>class</code></em></span>] { + type slave; + [<span class="optional"> allow-notify { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-query { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-transfer { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> allow-update-forwarding { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> update-check-ksk <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> also-notify { <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> check-names (<code class="constant">warn</code>|<code class="constant">fail</code>|<code class="constant">ignore</code>) ; </span>] + [<span class="optional"> dialup <em class="replaceable"><code>dialup_option</code></em> ; </span>] + [<span class="optional"> file <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> masterfile-format (<code class="constant">text</code>|<code class="constant">raw</code>) ; </span>] + [<span class="optional"> journal <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> forward (<code class="constant">only</code>|<code class="constant">first</code>) ; </span>] + [<span class="optional"> forwarders { [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> ixfr-base <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> ixfr-tmp-file <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> maintain-ixfr-base <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> masters [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] { ( <em class="replaceable"><code>masters_list</code></em> | <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] [<span class="optional">key <em class="replaceable"><code>key</code></em></span>] ) ; [<span class="optional">...</span>] }; </span>] + [<span class="optional"> max-ixfr-log-size <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-transfer-idle-in <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-transfer-idle-out <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-transfer-time-in <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-transfer-time-out <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> notify <em class="replaceable"><code>yes_or_no</code></em> | <em class="replaceable"><code>explicit</code></em> | <em class="replaceable"><code>master-only</code></em> ; </span>] + [<span class="optional"> pubkey <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> transfer-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> transfer-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> alt-transfer-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> alt-transfer-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> use-alt-transfer-source <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> notify-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> notify-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> zone-statistics <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> database <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> min-refresh-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-refresh-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> min-retry-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-retry-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> multi-master <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> zero-no-soa-ttl <em class="replaceable"><code>yes_or_no</code></em> ; </span>] +}; + +zone <em class="replaceable"><code>zone_name</code></em> [<span class="optional"><em class="replaceable"><code>class</code></em></span>] { + type hint; + file <em class="replaceable"><code>string</code></em> ; + [<span class="optional"> delegation-only <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> check-names (<code class="constant">warn</code>|<code class="constant">fail</code>|<code class="constant">ignore</code>) ; // Not Implemented. </span>] +}; + +zone <em class="replaceable"><code>zone_name</code></em> [<span class="optional"><em class="replaceable"><code>class</code></em></span>] { + type stub; + [<span class="optional"> allow-query { <em class="replaceable"><code>address_match_list</code></em> }; </span>] + [<span class="optional"> check-names (<code class="constant">warn</code>|<code class="constant">fail</code>|<code class="constant">ignore</code>) ; </span>] + [<span class="optional"> dialup <em class="replaceable"><code>dialup_option</code></em> ; </span>] + [<span class="optional"> delegation-only <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> file <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> masterfile-format (<code class="constant">text</code>|<code class="constant">raw</code>) ; </span>] + [<span class="optional"> forward (<code class="constant">only</code>|<code class="constant">first</code>) ; </span>] + [<span class="optional"> forwarders { [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> masters [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] { ( <em class="replaceable"><code>masters_list</code></em> | <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] [<span class="optional">key <em class="replaceable"><code>key</code></em></span>] ) ; [<span class="optional">...</span>] }; </span>] + [<span class="optional"> max-transfer-idle-in <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-transfer-time-in <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> pubkey <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>number</code></em> <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> transfer-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> transfer-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> alt-transfer-source (<em class="replaceable"><code>ip4_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> alt-transfer-source-v6 (<em class="replaceable"><code>ip6_addr</code></em> | <code class="constant">*</code>) [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; </span>] + [<span class="optional"> use-alt-transfer-source <em class="replaceable"><code>yes_or_no</code></em>; </span>] + [<span class="optional"> zone-statistics <em class="replaceable"><code>yes_or_no</code></em> ; </span>] + [<span class="optional"> database <em class="replaceable"><code>string</code></em> ; </span>] + [<span class="optional"> min-refresh-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-refresh-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> min-retry-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> max-retry-time <em class="replaceable"><code>number</code></em> ; </span>] + [<span class="optional"> multi-master <em class="replaceable"><code>yes_or_no</code></em> ; </span>] +}; + +zone <em class="replaceable"><code>zone_name</code></em> [<span class="optional"><em class="replaceable"><code>class</code></em></span>] { + type forward; + [<span class="optional"> forward (<code class="constant">only</code>|<code class="constant">first</code>) ; </span>] + [<span class="optional"> forwarders { [<span class="optional"> <em class="replaceable"><code>ip_addr</code></em> [<span class="optional">port <em class="replaceable"><code>ip_port</code></em></span>] ; ... </span>] }; </span>] + [<span class="optional"> delegation-only <em class="replaceable"><code>yes_or_no</code></em> ; </span>] +}; + +zone <em class="replaceable"><code>zone_name</code></em> [<span class="optional"><em class="replaceable"><code>class</code></em></span>] { + type delegation-only; +}; + +</pre> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2586798"></a><span><strong class="command">zone</strong></span> Statement Definition and Usage</h3></div></div></div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2586806"></a>Zone Types</h4></div></div></div> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + <code class="varname">master</code> + </p> + </td> +<td> + <p> + The server has a master copy of the data + for the zone and will be able to provide authoritative + answers for + it. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">slave</code> + </p> + </td> +<td> + <p> + A slave zone is a replica of a master + zone. The <span><strong class="command">masters</strong></span> list + specifies one or more IP addresses + of master servers that the slave contacts to update + its copy of the zone. + Masters list elements can also be names of other + masters lists. + By default, transfers are made from port 53 on the + servers; this can + be changed for all servers by specifying a port number + before the + list of IP addresses, or on a per-server basis after + the IP address. + Authentication to the master can also be done with + per-server TSIG keys. + If a file is specified, then the + replica will be written to this file whenever the zone + is changed, + and reloaded from this file on a server restart. Use + of a file is + recommended, since it often speeds server startup and + eliminates + a needless waste of bandwidth. Note that for large + numbers (in the + tens or hundreds of thousands) of zones per server, it + is best to + use a two-level naming scheme for zone filenames. For + example, + a slave server for the zone <code class="literal">example.com</code> might place + the zone contents into a file called + <code class="filename">ex/example.com</code> where <code class="filename">ex/</code> is + just the first two letters of the zone name. (Most + operating systems + behave very slowly if you put 100 000 files into + a single directory.) + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">stub</code> + </p> + </td> +<td> + <p> + A stub zone is similar to a slave zone, + except that it replicates only the NS records of a + master zone instead + of the entire zone. Stub zones are not a standard part + of the DNS; + they are a feature specific to the <acronym class="acronym">BIND</acronym> implementation. + </p> + + <p> + Stub zones can be used to eliminate the need for glue + NS record + in a parent zone at the expense of maintaining a stub + zone entry and + a set of name server addresses in <code class="filename">named.conf</code>. + This usage is not recommended for new configurations, + and BIND 9 + supports it only in a limited way. + In <acronym class="acronym">BIND</acronym> 4/8, zone + transfers of a parent zone + included the NS records from stub children of that + zone. This meant + that, in some cases, users could get away with + configuring child stubs + only in the master server for the parent zone. <acronym class="acronym">BIND</acronym> + 9 never mixes together zone data from different zones + in this + way. Therefore, if a <acronym class="acronym">BIND</acronym> 9 master serving a parent + zone has child stub zones configured, all the slave + servers for the + parent zone also need to have the same child stub + zones + configured. + </p> + + <p> + Stub zones can also be used as a way of forcing the + resolution + of a given domain to use a particular set of + authoritative servers. + For example, the caching name servers on a private + network using + RFC1918 addressing may be configured with stub zones + for + <code class="literal">10.in-addr.arpa</code> + to use a set of internal name servers as the + authoritative + servers for that domain. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">forward</code> + </p> + </td> +<td> + <p> + A "forward zone" is a way to configure + forwarding on a per-domain basis. A <span><strong class="command">zone</strong></span> statement + of type <span><strong class="command">forward</strong></span> can + contain a <span><strong class="command">forward</strong></span> + and/or <span><strong class="command">forwarders</strong></span> + statement, + which will apply to queries within the domain given by + the zone + name. If no <span><strong class="command">forwarders</strong></span> + statement is present or + an empty list for <span><strong class="command">forwarders</strong></span> is given, then no + forwarding will be done for the domain, canceling the + effects of + any forwarders in the <span><strong class="command">options</strong></span> statement. Thus + if you want to use this type of zone to change the + behavior of the + global <span><strong class="command">forward</strong></span> option + (that is, "forward first" + to, then "forward only", or vice versa, but want to + use the same + servers as set globally) you need to re-specify the + global forwarders. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">hint</code> + </p> + </td> +<td> + <p> + The initial set of root name servers is + specified using a "hint zone". When the server starts + up, it uses + the root hints to find a root name server and get the + most recent + list of root name servers. If no hint zone is + specified for class + IN, the server uses a compiled-in default set of root + servers hints. + Classes other than IN have no built-in defaults hints. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">delegation-only</code> + </p> + </td> +<td> + <p> + This is used to enforce the delegation-only + status of infrastructure zones (e.g. COM, NET, ORG). + Any answer that + is received without an explicit or implicit delegation + in the authority + section will be treated as NXDOMAIN. This does not + apply to the zone + apex. This should not be applied to leaf zones. + </p> + <p> + <code class="varname">delegation-only</code> has no + effect on answers received + from forwarders. + </p> + </td> +</tr> +</tbody> +</table></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2587362"></a>Class</h4></div></div></div> +<p> + The zone's name may optionally be followed by a class. If + a class is not specified, class <code class="literal">IN</code> (for <code class="varname">Internet</code>), + is assumed. This is correct for the vast majority of cases. + </p> +<p> + The <code class="literal">hesiod</code> class is + named for an information service from MIT's Project Athena. It + is + used to share information about various systems databases, such + as users, groups, printers and so on. The keyword + <code class="literal">HS</code> is + a synonym for hesiod. + </p> +<p> + Another MIT development is Chaosnet, a LAN protocol created + in the mid-1970s. Zone data for it can be specified with the <code class="literal">CHAOS</code> class. + </p> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2587395"></a>Zone Options</h4></div></div></div> +<div class="variablelist"><dl> +<dt><span class="term"><span><strong class="command">allow-notify</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">allow-notify</strong></span> in <a href="Bv9ARM.ch06.html#access_control" title="Access Control">the section called “Access Control”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-query</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">allow-query</strong></span> in <a href="Bv9ARM.ch06.html#access_control" title="Access Control">the section called “Access Control”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-transfer</strong></span></span></dt> +<dd><p> + See the description of <span><strong class="command">allow-transfer</strong></span> + in <a href="Bv9ARM.ch06.html#access_control" title="Access Control">the section called “Access Control”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-update</strong></span></span></dt> +<dd><p> + See the description of <span><strong class="command">allow-update</strong></span> + in <a href="Bv9ARM.ch06.html#access_control" title="Access Control">the section called “Access Control”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">update-policy</strong></span></span></dt> +<dd><p> + Specifies a "Simple Secure Update" policy. See + <a href="Bv9ARM.ch06.html#dynamic_update_policies" title="Dynamic Update Policies">the section called “Dynamic Update Policies”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">allow-update-forwarding</strong></span></span></dt> +<dd><p> + See the description of <span><strong class="command">allow-update-forwarding</strong></span> + in <a href="Bv9ARM.ch06.html#access_control" title="Access Control">the section called “Access Control”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">also-notify</strong></span></span></dt> +<dd><p> + Only meaningful if <span><strong class="command">notify</strong></span> + is + active for this zone. The set of machines that will + receive a + <code class="literal">DNS NOTIFY</code> message + for this zone is made up of all the listed name servers + (other than + the primary master) for the zone plus any IP addresses + specified + with <span><strong class="command">also-notify</strong></span>. A port + may be specified + with each <span><strong class="command">also-notify</strong></span> + address to send the notify + messages to a port other than the default of 53. + <span><strong class="command">also-notify</strong></span> is not + meaningful for stub zones. + The default is the empty list. + </p></dd> +<dt><span class="term"><span><strong class="command">check-names</strong></span></span></dt> +<dd><p> + This option is used to restrict the character set and + syntax of + certain domain names in master files and/or DNS responses + received from the + network. The default varies according to zone type. For <span><strong class="command">master</strong></span> zones the default is <span><strong class="command">fail</strong></span>. For <span><strong class="command">slave</strong></span> + zones the default is <span><strong class="command">warn</strong></span>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-mx</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">check-mx</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-wildcard</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">check-wildcard</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-integrity</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">check-integrity</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">check-sibling</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">check-sibling</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">zero-no-soa-ttl</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">zero-no-soa-ttl</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">update-check-ksk</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">update-check-ksk</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">database</strong></span></span></dt> +<dd> +<p> + Specify the type of database to be used for storing the + zone data. The string following the <span><strong class="command">database</strong></span> keyword + is interpreted as a list of whitespace-delimited words. + The first word + identifies the database type, and any subsequent words are + passed + as arguments to the database to be interpreted in a way + specific + to the database type. + </p> +<p> + The default is <strong class="userinput"><code>"rbt"</code></strong>, BIND 9's + native in-memory + red-black-tree database. This database does not take + arguments. + </p> +<p> + Other values are possible if additional database drivers + have been linked into the server. Some sample drivers are + included + with the distribution but none are linked in by default. + </p> +</dd> +<dt><span class="term"><span><strong class="command">dialup</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">dialup</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">delegation-only</strong></span></span></dt> +<dd><p> + The flag only applies to hint and stub zones. If set + to <strong class="userinput"><code>yes</code></strong>, then the zone will also be + treated as if it + is also a delegation-only type zone. + </p></dd> +<dt><span class="term"><span><strong class="command">forward</strong></span></span></dt> +<dd><p> + Only meaningful if the zone has a forwarders + list. The <span><strong class="command">only</strong></span> value causes + the lookup to fail + after trying the forwarders and getting no answer, while <span><strong class="command">first</strong></span> would + allow a normal lookup to be tried. + </p></dd> +<dt><span class="term"><span><strong class="command">forwarders</strong></span></span></dt> +<dd><p> + Used to override the list of global forwarders. + If it is not specified in a zone of type <span><strong class="command">forward</strong></span>, + no forwarding is done for the zone and the global options are + not used. + </p></dd> +<dt><span class="term"><span><strong class="command">ixfr-base</strong></span></span></dt> +<dd><p> + Was used in <acronym class="acronym">BIND</acronym> 8 to + specify the name + of the transaction log (journal) file for dynamic update + and IXFR. + <acronym class="acronym">BIND</acronym> 9 ignores the option + and constructs the name of the journal + file by appending "<code class="filename">.jnl</code>" + to the name of the + zone file. + </p></dd> +<dt><span class="term"><span><strong class="command">ixfr-tmp-file</strong></span></span></dt> +<dd><p> + Was an undocumented option in <acronym class="acronym">BIND</acronym> 8. + Ignored in <acronym class="acronym">BIND</acronym> 9. + </p></dd> +<dt><span class="term"><span><strong class="command">journal</strong></span></span></dt> +<dd><p> + Allow the default journal's filename to be overridden. + The default is the zone's filename with "<code class="filename">.jnl</code>" appended. + This is applicable to <span><strong class="command">master</strong></span> and <span><strong class="command">slave</strong></span> zones. + </p></dd> +<dt><span class="term"><span><strong class="command">max-transfer-time-in</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">max-transfer-time-in</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">max-transfer-idle-in</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">max-transfer-idle-in</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">max-transfer-time-out</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">max-transfer-time-out</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">max-transfer-idle-out</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">max-transfer-idle-out</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">notify</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">notify</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">notify-delay</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">notify-delay</strong></span> in <a href="Bv9ARM.ch06.html#tuning" title="Tuning">the section called “Tuning”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">pubkey</strong></span></span></dt> +<dd><p> + In <acronym class="acronym">BIND</acronym> 8, this option was + intended for specifying + a public zone key for verification of signatures in DNSSEC + signed + zones when they are loaded from disk. <acronym class="acronym">BIND</acronym> 9 does not verify signatures + on load and ignores the option. + </p></dd> +<dt><span class="term"><span><strong class="command">zone-statistics</strong></span></span></dt> +<dd><p> + If <strong class="userinput"><code>yes</code></strong>, the server will keep + statistical + information for this zone, which can be dumped to the + <span><strong class="command">statistics-file</strong></span> defined in + the server options. + </p></dd> +<dt><span class="term"><span><strong class="command">sig-validity-interval</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">sig-validity-interval</strong></span> in <a href="Bv9ARM.ch06.html#tuning" title="Tuning">the section called “Tuning”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">transfer-source</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">transfer-source</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">transfer-source-v6</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">transfer-source-v6</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">alt-transfer-source</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">alt-transfer-source</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">alt-transfer-source-v6</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">alt-transfer-source-v6</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">use-alt-transfer-source</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">use-alt-transfer-source</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">notify-source</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">notify-source</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">notify-source-v6</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">notify-source-v6</strong></span> in <a href="Bv9ARM.ch06.html#zone_transfers" title="Zone Transfers">the section called “Zone Transfers”</a>. + </p></dd> +<dt> +<span class="term"><span><strong class="command">min-refresh-time</strong></span>, </span><span class="term"><span><strong class="command">max-refresh-time</strong></span>, </span><span class="term"><span><strong class="command">min-retry-time</strong></span>, </span><span class="term"><span><strong class="command">max-retry-time</strong></span></span> +</dt> +<dd><p> + See the description in <a href="Bv9ARM.ch06.html#tuning" title="Tuning">the section called “Tuning”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">ixfr-from-differences</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">ixfr-from-differences</strong></span> in <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">key-directory</strong></span></span></dt> +<dd><p> + See the description of + <span><strong class="command">key-directory</strong></span> in <a href="Bv9ARM.ch06.html#options" title="options Statement Definition and + Usage">the section called “<span><strong class="command">options</strong></span> Statement Definition and + Usage”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">multi-master</strong></span></span></dt> +<dd><p> + See the description of <span><strong class="command">multi-master</strong></span> in + <a href="Bv9ARM.ch06.html#boolean_options" title="Boolean Options">the section called “Boolean Options”</a>. + </p></dd> +<dt><span class="term"><span><strong class="command">masterfile-format</strong></span></span></dt> +<dd><p> + See the description of <span><strong class="command">masterfile-format</strong></span> + in <a href="Bv9ARM.ch06.html#tuning" title="Tuning">the section called “Tuning”</a>. + </p></dd> +</dl></div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="dynamic_update_policies"></a>Dynamic Update Policies</h4></div></div></div> +<p> + <acronym class="acronym">BIND</acronym> 9 supports two alternative + methods of granting clients + the right to perform dynamic updates to a zone, + configured by the <span><strong class="command">allow-update</strong></span> + and + <span><strong class="command">update-policy</strong></span> option, + respectively. + </p> +<p> + The <span><strong class="command">allow-update</strong></span> clause works the + same + way as in previous versions of <acronym class="acronym">BIND</acronym>. It grants given clients the + permission to update any record of any name in the zone. + </p> +<p> + The <span><strong class="command">update-policy</strong></span> clause is new + in <acronym class="acronym">BIND</acronym> + 9 and allows more fine-grained control over what updates are + allowed. + A set of rules is specified, where each rule either grants or + denies + permissions for one or more names to be updated by one or more + identities. + If the dynamic update request message is signed (that is, it + includes + either a TSIG or SIG(0) record), the identity of the signer can + be determined. + </p> +<p> + Rules are specified in the <span><strong class="command">update-policy</strong></span> zone + option, and are only meaningful for master zones. When the <span><strong class="command">update-policy</strong></span> statement + is present, it is a configuration error for the <span><strong class="command">allow-update</strong></span> statement + to be present. The <span><strong class="command">update-policy</strong></span> + statement only + examines the signer of a message; the source address is not + relevant. + </p> +<p> + This is how a rule definition looks: + </p> +<pre class="programlisting"> +( <span><strong class="command">grant</strong></span> | <span><strong class="command">deny</strong></span> ) <em class="replaceable"><code>identity</code></em> <em class="replaceable"><code>nametype</code></em> <em class="replaceable"><code>name</code></em> [<span class="optional"> <em class="replaceable"><code>types</code></em> </span>] +</pre> +<p> + Each rule grants or denies privileges. Once a message has + successfully matched a rule, the operation is immediately + granted + or denied and no further rules are examined. A rule is matched + when the signer matches the identity field, the name matches the + name field in accordance with the nametype field, and the type + matches + the types specified in the type field. + </p> +<p> + The identity field specifies a name or a wildcard name. + Normally, this + is the name of the TSIG or SIG(0) key used to sign the update + request. When a + TKEY exchange has been used to create a shared secret, the + identity of the + shared secret is the same as the identity of the key used to + authenticate the + TKEY exchange. When the <em class="replaceable"><code>identity</code></em> field specifies a + wildcard name, it is subject to DNS wildcard expansion, so the + rule will apply + to multiple identities. The <em class="replaceable"><code>identity</code></em> field must + contain a fully-qualified domain name. + </p> +<p> + The <em class="replaceable"><code>nametype</code></em> field has 6 + values: + <code class="varname">name</code>, <code class="varname">subdomain</code>, + <code class="varname">wildcard</code>, <code class="varname">self</code>, + <code class="varname">selfsub</code>, and <code class="varname">selfwild</code>. + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + <code class="varname">name</code> + </p> + </td> +<td> + <p> + Exact-match semantics. This rule matches + when the name being updated is identical + to the contents of the + <em class="replaceable"><code>name</code></em> field. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">subdomain</code> + </p> + </td> +<td> + <p> + This rule matches when the name being updated + is a subdomain of, or identical to, the + contents of the <em class="replaceable"><code>name</code></em> + field. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">wildcard</code> + </p> + </td> +<td> + <p> + The <em class="replaceable"><code>name</code></em> field + is subject to DNS wildcard expansion, and + this rule matches when the name being updated + name is a valid expansion of the wildcard. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">self</code> + </p> + </td> +<td> + <p> + This rule matches when the name being updated + matches the contents of the + <em class="replaceable"><code>identity</code></em> field. + The <em class="replaceable"><code>name</code></em> field + is ignored, but should be the same as the + <em class="replaceable"><code>identity</code></em> field. + The <code class="varname">self</code> nametype is + most useful when allowing using one key per + name to update, where the key has the same + name as the name to be updated. The + <em class="replaceable"><code>identity</code></em> would + be specified as <code class="constant">*</code> (an asterisk) in + this case. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">selfsub</code> + </p> + </td> +<td> + <p> + This rule is similar to <code class="varname">self</code> + except that subdomains of <code class="varname">self</code> + can also be updated. + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="varname">selfwild</code> + </p> + </td> +<td> + <p> + This rule is similar to <code class="varname">self</code> + except that only subdomains of + <code class="varname">self</code> can be updated. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + In all cases, the <em class="replaceable"><code>name</code></em> + field must + specify a fully-qualified domain name. + </p> +<p> + If no types are explicitly specified, this rule matches all + types except + RRSIG, NS, SOA, and NSEC. Types may be specified by name, including + "ANY" (ANY matches all types except NSEC, which can never be + updated). + Note that when an attempt is made to delete all records + associated with a + name, the rules are checked for each existing record type. + </p> +</div> +</div> +</div> +<div class="sect1" lang="en"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="id2589080"></a>Zone File</h2></div></div></div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="types_of_resource_records_and_when_to_use_them"></a>Types of Resource Records and When to Use Them</h3></div></div></div> +<p> + This section, largely borrowed from RFC 1034, describes the + concept of a Resource Record (RR) and explains when each is used. + Since the publication of RFC 1034, several new RRs have been + identified + and implemented in the DNS. These are also included. + </p> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2589098"></a>Resource Records</h4></div></div></div> +<p> + A domain name identifies a node. Each node has a set of + resource information, which may be empty. The set of resource + information associated with a particular name is composed of + separate RRs. The order of RRs in a set is not significant and + need not be preserved by name servers, resolvers, or other + parts of the DNS. However, sorting of multiple RRs is + permitted for optimization purposes, for example, to specify + that a particular nearby server be tried first. See <a href="Bv9ARM.ch06.html#the_sortlist_statement" title="The sortlist Statement">the section called “The <span><strong class="command">sortlist</strong></span> Statement”</a> and <a href="Bv9ARM.ch06.html#rrset_ordering" title="RRset Ordering">the section called “RRset Ordering”</a>. + </p> +<p> + The components of a Resource Record are: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + owner name + </p> + </td> +<td> + <p> + The domain name where the RR is found. + </p> + </td> +</tr> +<tr> +<td> + <p> + type + </p> + </td> +<td> + <p> + An encoded 16-bit value that specifies + the type of the resource record. + </p> + </td> +</tr> +<tr> +<td> + <p> + TTL + </p> + </td> +<td> + <p> + The time-to-live of the RR. This field + is a 32-bit integer in units of seconds, and is + primarily used by + resolvers when they cache RRs. The TTL describes how + long a RR can + be cached before it should be discarded. + </p> + </td> +</tr> +<tr> +<td> + <p> + class + </p> + </td> +<td> + <p> + An encoded 16-bit value that identifies + a protocol family or instance of a protocol. + </p> + </td> +</tr> +<tr> +<td> + <p> + RDATA + </p> + </td> +<td> + <p> + The resource data. The format of the + data is type (and sometimes class) specific. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + The following are <span class="emphasis"><em>types</em></span> of valid RRs: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + A + </p> + </td> +<td> + <p> + A host address. In the IN class, this is a + 32-bit IP address. Described in RFC 1035. + </p> + </td> +</tr> +<tr> +<td> + <p> + AAAA + </p> + </td> +<td> + <p> + IPv6 address. Described in RFC 1886. + </p> + </td> +</tr> +<tr> +<td> + <p> + A6 + </p> + </td> +<td> + <p> + IPv6 address. This can be a partial + address (a suffix) and an indirection to the name + where the rest of the + address (the prefix) can be found. Experimental. + Described in RFC 2874. + </p> + </td> +</tr> +<tr> +<td> + <p> + AFSDB + </p> + </td> +<td> + <p> + Location of AFS database servers. + Experimental. Described in RFC 1183. + </p> + </td> +</tr> +<tr> +<td> + <p> + APL + </p> + </td> +<td> + <p> + Address prefix list. Experimental. + Described in RFC 3123. + </p> + </td> +</tr> +<tr> +<td> + <p> + CERT + </p> + </td> +<td> + <p> + Holds a digital certificate. + Described in RFC 2538. + </p> + </td> +</tr> +<tr> +<td> + <p> + CNAME + </p> + </td> +<td> + <p> + Identifies the canonical name of an alias. + Described in RFC 1035. + </p> + </td> +</tr> +<tr> +<td> + <p> + DNAME + </p> + </td> +<td> + <p> + Replaces the domain name specified with + another name to be looked up, effectively aliasing an + entire + subtree of the domain name space rather than a single + record + as in the case of the CNAME RR. + Described in RFC 2672. + </p> + </td> +</tr> +<tr> +<td> + <p> + DNSKEY + </p> + </td> +<td> + <p> + Stores a public key associated with a signed + DNS zone. Described in RFC 4034. + </p> + </td> +</tr> +<tr> +<td> + <p> + DS + </p> + </td> +<td> + <p> + Stores the hash of a public key associated with a + signed DNS zone. Described in RFC 4034. + </p> + </td> +</tr> +<tr> +<td> + <p> + GPOS + </p> + </td> +<td> + <p> + Specifies the global position. Superseded by LOC. + </p> + </td> +</tr> +<tr> +<td> + <p> + HINFO + </p> + </td> +<td> + <p> + Identifies the CPU and OS used by a host. + Described in RFC 1035. + </p> + </td> +</tr> +<tr> +<td> + <p> + ISDN + </p> + </td> +<td> + <p> + Representation of ISDN addresses. + Experimental. Described in RFC 1183. + </p> + </td> +</tr> +<tr> +<td> + <p> + KEY + </p> + </td> +<td> + <p> + Stores a public key associated with a + DNS name. Used in original DNSSEC; replaced + by DNSKEY in DNSSECbis, but still used with + SIG(0). Described in RFCs 2535 and 2931. + </p> + </td> +</tr> +<tr> +<td> + <p> + KX + </p> + </td> +<td> + <p> + Identifies a key exchanger for this + DNS name. Described in RFC 2230. + </p> + </td> +</tr> +<tr> +<td> + <p> + LOC + </p> + </td> +<td> + <p> + For storing GPS info. Described in RFC 1876. + Experimental. + </p> + </td> +</tr> +<tr> +<td> + <p> + MX + </p> + </td> +<td> + <p> + Identifies a mail exchange for the domain with + a 16-bit preference value (lower is better) + followed by the host name of the mail exchange. + Described in RFC 974, RFC 1035. + </p> + </td> +</tr> +<tr> +<td> + <p> + NAPTR + </p> + </td> +<td> + <p> + Name authority pointer. Described in RFC 2915. + </p> + </td> +</tr> +<tr> +<td> + <p> + NSAP + </p> + </td> +<td> + <p> + A network service access point. + Described in RFC 1706. + </p> + </td> +</tr> +<tr> +<td> + <p> + NS + </p> + </td> +<td> + <p> + The authoritative name server for the + domain. Described in RFC 1035. + </p> + </td> +</tr> +<tr> +<td> + <p> + NSEC + </p> + </td> +<td> + <p> + Used in DNSSECbis to securely indicate that + RRs with an owner name in a certain name interval do + not exist in + a zone and indicate what RR types are present for an + existing name. + Described in RFC 4034. + </p> + </td> +</tr> +<tr> +<td> + <p> + NXT + </p> + </td> +<td> + <p> + Used in DNSSEC to securely indicate that + RRs with an owner name in a certain name interval do + not exist in + a zone and indicate what RR types are present for an + existing name. + Used in original DNSSEC; replaced by NSEC in + DNSSECbis. + Described in RFC 2535. + </p> + </td> +</tr> +<tr> +<td> + <p> + PTR + </p> + </td> +<td> + <p> + A pointer to another part of the domain + name space. Described in RFC 1035. + </p> + </td> +</tr> +<tr> +<td> + <p> + PX + </p> + </td> +<td> + <p> + Provides mappings between RFC 822 and X.400 + addresses. Described in RFC 2163. + </p> + </td> +</tr> +<tr> +<td> + <p> + RP + </p> + </td> +<td> + <p> + Information on persons responsible + for the domain. Experimental. Described in RFC 1183. + </p> + </td> +</tr> +<tr> +<td> + <p> + RRSIG + </p> + </td> +<td> + <p> + Contains DNSSECbis signature data. Described + in RFC 4034. + </p> + </td> +</tr> +<tr> +<td> + <p> + RT + </p> + </td> +<td> + <p> + Route-through binding for hosts that + do not have their own direct wide area network + addresses. + Experimental. Described in RFC 1183. + </p> + </td> +</tr> +<tr> +<td> + <p> + SIG + </p> + </td> +<td> + <p> + Contains DNSSEC signature data. Used in + original DNSSEC; replaced by RRSIG in + DNSSECbis, but still used for SIG(0). + Described in RFCs 2535 and 2931. + </p> + </td> +</tr> +<tr> +<td> + <p> + SOA + </p> + </td> +<td> + <p> + Identifies the start of a zone of authority. + Described in RFC 1035. + </p> + </td> +</tr> +<tr> +<td> + <p> + SRV + </p> + </td> +<td> + <p> + Information about well known network + services (replaces WKS). Described in RFC 2782. + </p> + </td> +</tr> +<tr> +<td> + <p> + TXT + </p> + </td> +<td> + <p> + Text records. Described in RFC 1035. + </p> + </td> +</tr> +<tr> +<td> + <p> + WKS + </p> + </td> +<td> + <p> + Information about which well known + network services, such as SMTP, that a domain + supports. Historical. + </p> + </td> +</tr> +<tr> +<td> + <p> + X25 + </p> + </td> +<td> + <p> + Representation of X.25 network addresses. + Experimental. Described in RFC 1183. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + The following <span class="emphasis"><em>classes</em></span> of resource records + are currently valid in the DNS: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + IN + </p> + </td> +<td> + <p> + The Internet. + </p> + </td> +</tr> +<tr> +<td> + <p> + CH + </p> + </td> +<td> + <p> + Chaosnet, a LAN protocol created at MIT in the + mid-1970s. + Rarely used for its historical purpose, but reused for + BIND's + built-in server information zones, e.g., + <code class="literal">version.bind</code>. + </p> + </td> +</tr> +<tr> +<td> + <p> + HS + </p> + </td> +<td> + <p> + Hesiod, an information service + developed by MIT's Project Athena. It is used to share + information + about various systems databases, such as users, + groups, printers + and so on. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + The owner name is often implicit, rather than forming an + integral + part of the RR. For example, many name servers internally form + tree + or hash structures for the name space, and chain RRs off nodes. + The remaining RR parts are the fixed header (type, class, TTL) + which is consistent for all RRs, and a variable part (RDATA) + that + fits the needs of the resource being described. + </p> +<p> + The meaning of the TTL field is a time limit on how long an + RR can be kept in a cache. This limit does not apply to + authoritative + data in zones; it is also timed out, but by the refreshing + policies + for the zone. The TTL is assigned by the administrator for the + zone where the data originates. While short TTLs can be used to + minimize caching, and a zero TTL prohibits caching, the + realities + of Internet performance suggest that these times should be on + the + order of days for the typical host. If a change can be + anticipated, + the TTL can be reduced prior to the change to minimize + inconsistency + during the change, and then increased back to its former value + following + the change. + </p> +<p> + The data in the RDATA section of RRs is carried as a combination + of binary strings and domain names. The domain names are + frequently + used as "pointers" to other data in the DNS. + </p> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2590513"></a>Textual expression of RRs</h4></div></div></div> +<p> + RRs are represented in binary form in the packets of the DNS + protocol, and are usually represented in highly encoded form + when + stored in a name server or resolver. In the examples provided + in + RFC 1034, a style similar to that used in master files was + employed + in order to show the contents of RRs. In this format, most RRs + are shown on a single line, although continuation lines are + possible + using parentheses. + </p> +<p> + The start of the line gives the owner of the RR. If a line + begins with a blank, then the owner is assumed to be the same as + that of the previous RR. Blank lines are often included for + readability. + </p> +<p> + Following the owner, we list the TTL, type, and class of the + RR. Class and type use the mnemonics defined above, and TTL is + an integer before the type field. In order to avoid ambiguity + in + parsing, type and class mnemonics are disjoint, TTLs are + integers, + and the type mnemonic is always last. The IN class and TTL + values + are often omitted from examples in the interests of clarity. + </p> +<p> + The resource data or RDATA section of the RR are given using + knowledge of the typical representation for the data. + </p> +<p> + For example, we might show the RRs carried in a message as: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + <code class="literal">ISI.EDU.</code> + </p> + </td> +<td> + <p> + <code class="literal">MX</code> + </p> + </td> +<td> + <p> + <code class="literal">10 VENERA.ISI.EDU.</code> + </p> + </td> +</tr> +<tr> +<td> + <p></p> + </td> +<td> + <p> + <code class="literal">MX</code> + </p> + </td> +<td> + <p> + <code class="literal">10 VAXA.ISI.EDU</code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="literal">VENERA.ISI.EDU</code> + </p> + </td> +<td> + <p> + <code class="literal">A</code> + </p> + </td> +<td> + <p> + <code class="literal">128.9.0.32</code> + </p> + </td> +</tr> +<tr> +<td> + <p></p> + </td> +<td> + <p> + <code class="literal">A</code> + </p> + </td> +<td> + <p> + <code class="literal">10.1.0.52</code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="literal">VAXA.ISI.EDU</code> + </p> + </td> +<td> + <p> + <code class="literal">A</code> + </p> + </td> +<td> + <p> + <code class="literal">10.2.0.27</code> + </p> + </td> +</tr> +<tr> +<td> + <p></p> + </td> +<td> + <p> + <code class="literal">A</code> + </p> + </td> +<td> + <p> + <code class="literal">128.9.0.33</code> + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + The MX RRs have an RDATA section which consists of a 16-bit + number followed by a domain name. The address RRs use a + standard + IP address format to contain a 32-bit internet address. + </p> +<p> + The above example shows six RRs, with two RRs at each of three + domain names. + </p> +<p> + Similarly we might see: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + <code class="literal">XX.LCS.MIT.EDU.</code> + </p> + </td> +<td> + <p> + <code class="literal">IN A</code> + </p> + </td> +<td> + <p> + <code class="literal">10.0.0.44</code> + </p> + </td> +</tr> +<tr> +<td> </td> +<td> + <p> + <code class="literal">CH A</code> + </p> + </td> +<td> + <p> + <code class="literal">MIT.EDU. 2420</code> + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + This example shows two addresses for + <code class="literal">XX.LCS.MIT.EDU</code>, each of a different class. + </p> +</div> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2591101"></a>Discussion of MX Records</h3></div></div></div> +<p> + As described above, domain servers store information as a + series of resource records, each of which contains a particular + piece of information about a given domain name (which is usually, + but not always, a host). The simplest way to think of a RR is as + a typed pair of data, a domain name matched with a relevant datum, + and stored with some additional type information to help systems + determine when the RR is relevant. + </p> +<p> + MX records are used to control delivery of email. The data + specified in the record is a priority and a domain name. The + priority + controls the order in which email delivery is attempted, with the + lowest number first. If two priorities are the same, a server is + chosen randomly. If no servers at a given priority are responding, + the mail transport agent will fall back to the next largest + priority. + Priority numbers do not have any absolute meaning — they are + relevant + only respective to other MX records for that domain name. The + domain + name given is the machine to which the mail will be delivered. + It <span class="emphasis"><em>must</em></span> have an associated address record + (A or AAAA) — CNAME is not sufficient. + </p> +<p> + For a given domain, if there is both a CNAME record and an + MX record, the MX record is in error, and will be ignored. + Instead, + the mail will be delivered to the server specified in the MX + record + pointed to by the CNAME. + </p> +<p> + For example: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +<col> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + <code class="literal">example.com.</code> + </p> + </td> +<td> + <p> + <code class="literal">IN</code> + </p> + </td> +<td> + <p> + <code class="literal">MX</code> + </p> + </td> +<td> + <p> + <code class="literal">10</code> + </p> + </td> +<td> + <p> + <code class="literal">mail.example.com.</code> + </p> + </td> +</tr> +<tr> +<td> + <p></p> + </td> +<td> + <p> + <code class="literal">IN</code> + </p> + </td> +<td> + <p> + <code class="literal">MX</code> + </p> + </td> +<td> + <p> + <code class="literal">10</code> + </p> + </td> +<td> + <p> + <code class="literal">mail2.example.com.</code> + </p> + </td> +</tr> +<tr> +<td> + <p></p> + </td> +<td> + <p> + <code class="literal">IN</code> + </p> + </td> +<td> + <p> + <code class="literal">MX</code> + </p> + </td> +<td> + <p> + <code class="literal">20</code> + </p> + </td> +<td> + <p> + <code class="literal">mail.backup.org.</code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="literal">mail.example.com.</code> + </p> + </td> +<td> + <p> + <code class="literal">IN</code> + </p> + </td> +<td> + <p> + <code class="literal">A</code> + </p> + </td> +<td> + <p> + <code class="literal">10.0.0.1</code> + </p> + </td> +<td> + <p></p> + </td> +</tr> +<tr> +<td> + <p> + <code class="literal">mail2.example.com.</code> + </p> + </td> +<td> + <p> + <code class="literal">IN</code> + </p> + </td> +<td> + <p> + <code class="literal">A</code> + </p> + </td> +<td> + <p> + <code class="literal">10.0.0.2</code> + </p> + </td> +<td> + <p></p> + </td> +</tr> +</tbody> +</table></div> +<p> + Mail delivery will be attempted to <code class="literal">mail.example.com</code> and + <code class="literal">mail2.example.com</code> (in + any order), and if neither of those succeed, delivery to <code class="literal">mail.backup.org</code> will + be attempted. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="Setting_TTLs"></a>Setting TTLs</h3></div></div></div> +<p> + The time-to-live of the RR field is a 32-bit integer represented + in units of seconds, and is primarily used by resolvers when they + cache RRs. The TTL describes how long a RR can be cached before it + should be discarded. The following three types of TTL are + currently + used in a zone file. + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + SOA + </p> + </td> +<td> + <p> + The last field in the SOA is the negative + caching TTL. This controls how long other servers will + cache no-such-domain + (NXDOMAIN) responses from you. + </p> + <p> + The maximum time for + negative caching is 3 hours (3h). + </p> + </td> +</tr> +<tr> +<td> + <p> + $TTL + </p> + </td> +<td> + <p> + The $TTL directive at the top of the + zone file (before the SOA) gives a default TTL for every + RR without + a specific TTL set. + </p> + </td> +</tr> +<tr> +<td> + <p> + RR TTLs + </p> + </td> +<td> + <p> + Each RR can have a TTL as the second + field in the RR, which will control how long other + servers can cache + the it. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + All of these TTLs default to units of seconds, though units + can be explicitly specified, for example, <code class="literal">1h30m</code>. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2591653"></a>Inverse Mapping in IPv4</h3></div></div></div> +<p> + Reverse name resolution (that is, translation from IP address + to name) is achieved by means of the <span class="emphasis"><em>in-addr.arpa</em></span> domain + and PTR records. Entries in the in-addr.arpa domain are made in + least-to-most significant order, read left to right. This is the + opposite order to the way IP addresses are usually written. Thus, + a machine with an IP address of 10.1.2.3 would have a + corresponding + in-addr.arpa name of + 3.2.1.10.in-addr.arpa. This name should have a PTR resource record + whose data field is the name of the machine or, optionally, + multiple + PTR records if the machine has more than one name. For example, + in the [<span class="optional">example.com</span>] domain: + </p> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p> + <code class="literal">$ORIGIN</code> + </p> + </td> +<td> + <p> + <code class="literal">2.1.10.in-addr.arpa</code> + </p> + </td> +</tr> +<tr> +<td> + <p> + <code class="literal">3</code> + </p> + </td> +<td> + <p> + <code class="literal">IN PTR foo.example.com.</code> + </p> + </td> +</tr> +</tbody> +</table></div> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + The <span><strong class="command">$ORIGIN</strong></span> lines in the examples + are for providing context to the examples only — they do not + necessarily + appear in the actual usage. They are only used here to indicate + that the example is relative to the listed origin. + </p> +</div> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2591848"></a>Other Zone File Directives</h3></div></div></div> +<p> + The Master File Format was initially defined in RFC 1035 and + has subsequently been extended. While the Master File Format + itself + is class independent all records in a Master File must be of the + same + class. + </p> +<p> + Master File Directives include <span><strong class="command">$ORIGIN</strong></span>, <span><strong class="command">$INCLUDE</strong></span>, + and <span><strong class="command">$TTL.</strong></span> + </p> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2591870"></a>The <span><strong class="command">$ORIGIN</strong></span> Directive</h4></div></div></div> +<p> + Syntax: <span><strong class="command">$ORIGIN</strong></span> + <em class="replaceable"><code>domain-name</code></em> + [<span class="optional"><em class="replaceable"><code>comment</code></em></span>] + </p> +<p><span><strong class="command">$ORIGIN</strong></span> + sets the domain name that will be appended to any + unqualified records. When a zone is first read in there + is an implicit <span><strong class="command">$ORIGIN</strong></span> + <<code class="varname">zone-name</code>><span><strong class="command">.</strong></span> + The current <span><strong class="command">$ORIGIN</strong></span> is appended to + the domain specified in the <span><strong class="command">$ORIGIN</strong></span> + argument if it is not absolute. + </p> +<pre class="programlisting"> +$ORIGIN example.com. +WWW CNAME MAIN-SERVER +</pre> +<p> + is equivalent to + </p> +<pre class="programlisting"> +WWW.EXAMPLE.COM. CNAME MAIN-SERVER.EXAMPLE.COM. +</pre> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2592000"></a>The <span><strong class="command">$INCLUDE</strong></span> Directive</h4></div></div></div> +<p> + Syntax: <span><strong class="command">$INCLUDE</strong></span> + <em class="replaceable"><code>filename</code></em> + [<span class="optional"> +<em class="replaceable"><code>origin</code></em> </span>] + [<span class="optional"> <em class="replaceable"><code>comment</code></em> </span>] + </p> +<p> + Read and process the file <code class="filename">filename</code> as + if it were included into the file at this point. If <span><strong class="command">origin</strong></span> is + specified the file is processed with <span><strong class="command">$ORIGIN</strong></span> set + to that value, otherwise the current <span><strong class="command">$ORIGIN</strong></span> is + used. + </p> +<p> + The origin and the current domain name + revert to the values they had prior to the <span><strong class="command">$INCLUDE</strong></span> once + the file has been read. + </p> +<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Note</h3> +<p> + RFC 1035 specifies that the current origin should be restored + after + an <span><strong class="command">$INCLUDE</strong></span>, but it is silent + on whether the current + domain name should also be restored. BIND 9 restores both of + them. + This could be construed as a deviation from RFC 1035, a + feature, or both. + </p> +</div> +</div> +<div class="sect3" lang="en"> +<div class="titlepage"><div><div><h4 class="title"> +<a name="id2592069"></a>The <span><strong class="command">$TTL</strong></span> Directive</h4></div></div></div> +<p> + Syntax: <span><strong class="command">$TTL</strong></span> + <em class="replaceable"><code>default-ttl</code></em> + [<span class="optional"> +<em class="replaceable"><code>comment</code></em> </span>] + </p> +<p> + Set the default Time To Live (TTL) for subsequent records + with undefined TTLs. Valid TTLs are of the range 0-2147483647 + seconds. + </p> +<p><span><strong class="command">$TTL</strong></span> + is defined in RFC 2308. + </p> +</div> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="id2592173"></a><acronym class="acronym">BIND</acronym> Master File Extension: the <span><strong class="command">$GENERATE</strong></span> Directive</h3></div></div></div> +<p> + Syntax: <span><strong class="command">$GENERATE</strong></span> + <em class="replaceable"><code>range</code></em> + <em class="replaceable"><code>lhs</code></em> + [<span class="optional"><em class="replaceable"><code>ttl</code></em></span>] + [<span class="optional"><em class="replaceable"><code>class</code></em></span>] + <em class="replaceable"><code>type</code></em> + <em class="replaceable"><code>rhs</code></em> + [<span class="optional"><em class="replaceable"><code>comment</code></em></span>] + </p> +<p><span><strong class="command">$GENERATE</strong></span> + is used to create a series of resource records that only + differ from each other by an + iterator. <span><strong class="command">$GENERATE</strong></span> can be used to + easily generate the sets of records required to support + sub /24 reverse delegations described in RFC 2317: + Classless IN-ADDR.ARPA delegation. + </p> +<pre class="programlisting">$ORIGIN 0.0.192.IN-ADDR.ARPA. +$GENERATE 1-2 0 NS SERVER$.EXAMPLE. +$GENERATE 1-127 $ CNAME $.0</pre> +<p> + is equivalent to + </p> +<pre class="programlisting">0.0.0.192.IN-ADDR.ARPA NS SERVER1.EXAMPLE. +0.0.0.192.IN-ADDR.ARPA. NS SERVER2.EXAMPLE. +1.0.0.192.IN-ADDR.ARPA. CNAME 1.0.0.0.192.IN-ADDR.ARPA. +2.0.0.192.IN-ADDR.ARPA. CNAME 2.0.0.0.192.IN-ADDR.ARPA. +... +127.0.0.192.IN-ADDR.ARPA. CNAME 127.0.0.0.192.IN-ADDR.ARPA. +</pre> +<div class="informaltable"><table border="1"> +<colgroup> +<col> +<col> +</colgroup> +<tbody> +<tr> +<td> + <p><span><strong class="command">range</strong></span></p> + </td> +<td> + <p> + This can be one of two forms: start-stop + or start-stop/step. If the first form is used, then step + is set to + 1. All of start, stop and step must be positive. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">lhs</strong></span></p> + </td> +<td> + <p>This + describes the owner name of the resource records + to be created. Any single <span><strong class="command">$</strong></span> + (dollar sign) + symbols within the <span><strong class="command">lhs</strong></span> side + are replaced by the iterator value. + + To get a $ in the output, you need to escape the + <span><strong class="command">$</strong></span> using a backslash + <span><strong class="command">\</strong></span>, + e.g. <span><strong class="command">\$</strong></span>. The + <span><strong class="command">$</strong></span> may optionally be followed + by modifiers which change the offset from the + iterator, field width and base. + + Modifiers are introduced by a + <span><strong class="command">{</strong></span> (left brace) immediately following the + <span><strong class="command">$</strong></span> as + <span><strong class="command">${offset[,width[,base]]}</strong></span>. + For example, <span><strong class="command">${-20,3,d}</strong></span> + subtracts 20 from the current value, prints the + result as a decimal in a zero-padded field of + width 3. + + Available output forms are decimal + (<span><strong class="command">d</strong></span>), octal + (<span><strong class="command">o</strong></span>) and hexadecimal + (<span><strong class="command">x</strong></span> or <span><strong class="command">X</strong></span> + for uppercase). The default modifier is + <span><strong class="command">${0,0,d}</strong></span>. If the + <span><strong class="command">lhs</strong></span> is not absolute, the + current <span><strong class="command">$ORIGIN</strong></span> is appended + to the name. + </p> + <p> + For compatibility with earlier versions, <span><strong class="command">$$</strong></span> is still + recognized as indicating a literal $ in the output. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">ttl</strong></span></p> + </td> +<td> + <p> + Specifies the time-to-live of the generated records. If + not specified this will be inherited using the + normal ttl inheritance rules. + </p> + <p><span><strong class="command">class</strong></span> + and <span><strong class="command">ttl</strong></span> can be + entered in either order. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">class</strong></span></p> + </td> +<td> + <p> + Specifies the class of the generated records. + This must match the zone class if it is + specified. + </p> + <p><span><strong class="command">class</strong></span> + and <span><strong class="command">ttl</strong></span> can be + entered in either order. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">type</strong></span></p> + </td> +<td> + <p> + At present the only supported types are + PTR, CNAME, DNAME, A, AAAA and NS. + </p> + </td> +</tr> +<tr> +<td> + <p><span><strong class="command">rhs</strong></span></p> + </td> +<td> + <p> + <span><strong class="command">rhs</strong></span> is a domain name. It is processed + similarly to lhs. + </p> + </td> +</tr> +</tbody> +</table></div> +<p> + The <span><strong class="command">$GENERATE</strong></span> directive is a <acronym class="acronym">BIND</acronym> extension + and not part of the standard zone file format. + </p> +<p> + BIND 8 does not support the optional TTL and CLASS fields. + </p> +</div> +<div class="sect2" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="zonefile_format"></a>Additional File Formats</h3></div></div></div> +<p> + In addition to the standard textual format, BIND 9 + supports the ability to read or dump to zone files in + other formats. The <code class="constant">raw</code> format is + currently available as an additional format. It is a + binary format representing BIND 9's internal data + structure directly, thereby remarkably improving the + loading time. + </p> +<p> + For a primary server, a zone file in the + <code class="constant">raw</code> format is expected to be + generated from a textual zone file by the + <span><strong class="command">named-compilezone</strong></span> command. For a + secondary server or for a dynamic zone, it is automatically + generated (if this format is specified by the + <span><strong class="command">masterfile-format</strong></span> option) when + <span><strong class="command">named</strong></span> dumps the zone contents after + zone transfer or when applying prior updates. + </p> +<p> + If a zone file in a binary format needs manual modification, + it first must be converted to a textual form by the + <span><strong class="command">named-compilezone</strong></span> command. All + necessary modification should go to the text file, which + should then be converted to the binary form by the + <span><strong class="command">named-compilezone</strong></span> command again. + </p> +<p> + Although the <code class="constant">raw</code> format uses the + network byte order and avoids architecture-dependent + data alignment so that it is as much portable as + possible, it is primarily expected to be used inside + the same single system. In order to export a zone + file in the <code class="constant">raw</code> format or make a + portable backup of the file, it is recommended to + convert the file to the standard textual representation. + </p> +</div> +</div> +</div> +<div class="navfooter"> +<hr> +<table width="100%" summary="Navigation footer"> +<tr> +<td width="40%" align="left"> +<a accesskey="p" href="Bv9ARM.ch05.html">Prev</a> </td> +<td width="20%" align="center"> </td> +<td width="40%" align="right"> <a accesskey="n" href="Bv9ARM.ch07.html">Next</a> +</td> +</tr> +<tr> +<td width="40%" align="left" valign="top">Chapter 5. The <acronym class="acronym">BIND</acronym> 9 Lightweight Resolver </td> +<td width="20%" align="center"><a accesskey="h" href="Bv9ARM.html">Home</a></td> +<td width="40%" align="right" valign="top"> Chapter 7. <acronym class="acronym">BIND</acronym> 9 Security Considerations</td> +</tr> +</table> +</div> +</body> +</html> |
