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-rw-r--r--contrib/bind/doc/html/options.html391
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diff --git a/contrib/bind/doc/html/options.html b/contrib/bind/doc/html/options.html
index 515ee96..e3e09ef 100644
--- a/contrib/bind/doc/html/options.html
+++ b/contrib/bind/doc/html/options.html
@@ -13,6 +13,7 @@
<PRE>
options {
+ [ version <VAR>version_string</VAR>; ]
[ directory <VAR>path_name</VAR>; ]
[ named-xfer <VAR>path_name</VAR>; ]
[ dump-file <VAR>path_name</VAR>; ]
@@ -21,37 +22,55 @@ options {
[ statistics-file <VAR>path_name</VAR>; ]
[ auth-nxdomain <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
[ deallocate-on-exit <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
+ [ dialup <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
[ fake-iquery <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
[ fetch-glue <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
+ [ has-old-clients <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
[ host-statistics <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
[ multiple-cnames <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
[ notify <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
[ recursion <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
+ [ rfc2308-type1 <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
+ [ use-id-pool <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
+ [ treat-cr-as-space <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
+ [ also-notify { <VAR><A HREF="docdef.html">ip_addr</A></VAR>; [ <VAR><A HREF="docdef.html">ip_addr</A></VAR>; ... ] };
[ forward ( only | first ); ]
[ forwarders { [ <VAR><A HREF="docdef.html">in_addr</A></VAR> ; [ <VAR><A HREF="docdef.html">in_addr</A></VAR> ; ... ] ] }; ]
[ check-names ( master | slave | response ) ( warn | fail | ignore); ]
[ allow-query { <VAR>address_match_list</VAR> }; ]
[ allow-transfer { <VAR>address_match_list</VAR> }; ]
+ [ allow-recursion { <VAR>address_match_list</VAR> }; ]
+ [ blackhole { <VAR>address_match_list</VAR> }; ]
[ listen-on [ port <VAR><A HREF="docdef.html">ip_port</A></VAR> ] { <VAR>address_match_list</VAR> }; ]
[ query-source [ address ( <VAR><A HREF="docdef.html">ip_addr</A></VAR> | * ) ] [ port ( <VAR><A HREF="docdef.html">ip_port</A></VAR> | * ) ] ; ]
+ [ lame-ttl <VAR>number</VAR>; ]
[ max-transfer-time-in <VAR>number</VAR>; ]
+ [ max-ncache-ttl <VAR>number</VAR>; ]
+ [ min-roots <VAR>number</VAR>; ]
+ [ serial-queries <VAR>number</VAR>; ]
[ transfer-format ( one-answer | many-answers ); ]
[ transfers-in <VAR>number</VAR>; ]
[ transfers-out <VAR>number</VAR>; ]
[ transfers-per-ns <VAR>number</VAR>; ]
+ [ transfer-source <VAR><A HREF="docdef.html">ip_addr</A></VAR>; ]
+ [ maintain-ixfr-base <VAR><A HREF="docdef.html">yes_or_no</A></VAR>; ]
+ [ max-ixfr-log-size <VAR>number</VAR>; ]
[ coresize <VAR><A HREF="docdef.html">size_spec</A></VAR> ; ]
[ datasize <VAR><A HREF="docdef.html">size_spec</A></VAR> ; ]
[ files <VAR><A HREF="docdef.html">size_spec</A></VAR> ; ]
[ stacksize <VAR><A HREF="docdef.html">size_spec</A></VAR> ; ]
[ cleaning-interval <VAR>number</VAR>; ]
+ [ heartbeat-interval <VAR>number</VAR>; ]
[ interface-interval <VAR>number</VAR>; ]
[ statistics-interval <VAR>number</VAR>; ]
- [ topology { <VAR>address_match_list</VAR> }; ]
+ [ <A HREF="#topology">topology</A> { <VAR>address_match_list</VAR> }; ]
+ [ <A HREF="#sortlist">sortlist</A> { <VAR>address_match_list</VAR> }; ]
+ [ rrset-order { <VAR>order_spec</VAR> ; [ <VAR>order_spec</VAR> ; ... ] ] };
};
</PRE>
<HR>
-<A NAME="Usage"><H3>Definition and Use</H3></A>
+<A NAME="Usage"><H3>Definition and Usage</H3></A>
<P>The options statement sets up global options to be used by
BIND. This statement may appear at only once in a
@@ -63,6 +82,13 @@ an options block with each option set to its default will be used.</P>
<H4>Pathnames</H4>
<DL>
+<DT><CODE>version</CODE>
+<DD>
+The version the server should report via the <VAR>ndc</VAR> command
+or via a query of name <CODE>version.bind</CODE> in class <I>chaos</I>.
+The default is the real version number of the server, but some server
+operators prefer the string <CODE>"surely you must be joking"</CODE>.
+
<DT><CODE>directory</CODE>
<DD>
The working directory of the server. Any non-absolute
@@ -86,7 +112,7 @@ specified, the default is "named_dump.db".
<DT><CODE>memstatistics-file</CODE>
<DD>
-The pathname of the file the server writes memory usage statistics to on exit,
+The pathname of the file the server writes memory usage statistics to, on exit,
if <CODE>deallocate-on-exit</CODE> is <CODE>yes</CODE>. If not
specified, the default is "named.memstats".
@@ -110,7 +136,7 @@ specified, the default is "named.stats".
<DL>
<DT><CODE>auth-nxdomain</CODE>
<DD>
-If <CODE>yes</CODE>, then the <CODE>AA</CODE> bit is always set on
+If <CODE>yes</CODE>, the <CODE>AA</CODE> bit is always set on
NXDOMAIN responses, even if the server is not actually authoritative.
The default is <CODE>yes</CODE>. Do not turn off
<CODE>auth-nxdomain</CODE> unless you are sure you know what you are
@@ -118,12 +144,36 @@ doing, as some older software won't like it.
<DT><CODE>deallocate-on-exit</CODE>
<DD>
-If <CODE>yes</CODE>, then when the server exits it will painstakingly
-deallocate every object it allocated, and then write a memory usage report to
+If <CODE>yes</CODE>, the server will painstakingly deallocate every object it
+it allocated, when it exits, and then write a memory usage report to
the <CODE>memstatistics-file</CODE>. The default is <CODE>no</CODE>, because
it is faster to let the operating system clean up.
<CODE>deallocate-on-exit</CODE> is handy for detecting memory leaks.
+<DT><CODE>dialup</CODE>
+<DD>
+If <CODE>yes</CODE>, 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
+<CODE>heartbeat-interval</CODE> and hopefully during the one call.
+It also suppresses some of the normal zone maintainance traffic.
+The default is <CODE>no</CODE>. The <CODE>dialup</CODE>
+option may also be specified in the <CODE>zone</CODE> statement, in which
+case it overrides the <CODE>options dialup</CODE> statement.
+
+<P>
+If the zone is a <CODE>master</CODE> zone, the server will send out
+NOTIFY request to all the slaves. This will trigger the "zone up to
+date checking" in the slave (providing it supports NOTIFY), allowing
+the <CODE>slave</CODE> to verify the zone while the call us up.
+
+<P>
+If the zone is a <CODE>slave</CODE> or <CODE>stub</CODE> zone, the server
+will suppress the regular "zone up to date" queries and only perform
+them when the <CODE>heartbeat-interval</CODE> expires.
+
<DT><CODE>fake-iquery</CODE>
<DD>
If <CODE>yes</CODE>, the server will simulate the obsolete DNS query type
@@ -137,15 +187,29 @@ a response. <CODE>fetch-glue no</CODE> can be used in conjunction with
<CODE>recursion no</CODE> to prevent the server's cache from growing or
becoming corrupted (at the cost of requiring more work from the client).
+<DT><CODE>has-old-clients</CODE>
+<DD>
+Setting the option to <CODE>yes</CODE> is equivalent to setting the follow
+three options <CODE>auth-nxdomain yes;</CODE>, <CODE>maintain-ixfr-base
+yes;</CODE> and <CODE>rfc2308-type1 no;</CODE>.
+The use of <CODE>has-old-clients</CODE> with <CODE>auth-nxdomain</CODE>,
+<CODE>maintain-ixfr-base</CODE> and <CODE>rfc2308-type1</CODE> is order
+dependant.
+
<DT><CODE>host-statistics</CODE>
<DD>
-If <CODE>yes</CODE>, then statistics are kept for every host that the
+If <CODE>yes</CODE>, statistics are kept for every host that the
the nameserver interacts with. The default is <CODE>no</CODE>. <I>Note:</I>
turning on <CODE>host-statistics</CODE> can consume huge amounts of memory.
+<DT><CODE>maintain-ixfr-base</CODE>
+<DD>
+If <CODE>yes</CODE>, a transaction log is kept for
+Incremental Zone Transfer. The default is <CODE>no</CODE>.
+
<DT><CODE>multiple-cnames</CODE>
<DD>
-If <CODE>yes</CODE>, then multiple CNAME resource records will be
+If <CODE>yes</CODE>, multiple CNAME resource records will be
allowed for a domain name. The default is <CODE>no</CODE>. Allowing
multiple CNAME records is against standards and is not recommended.
Multiple CNAME support is available because previous versions of BIND
@@ -157,24 +221,62 @@ balancing by a number of sites.
If <CODE>yes</CODE> (the default), DNS NOTIFY messages are sent when a
zone the server is authoritative for changes. The use of NOTIFY
speeds convergence between the master and its slaves. Slave servers
-that receive a NOTIFY message and understand it will contact the
-master server for the zone and see if they need to do a zone transfer, and
-if they do, they will initiate it immediately. The <CODE>notify</CODE>
+that receive a NOTIFY message, and understand it, will contact the
+master server for the zone to see if they need to do a zone transfer. If
+they do, they will initiate it immediately. The <CODE>notify</CODE>
option may also be specified in the <CODE>zone</CODE> statement, in which
case it overrides the <CODE>options notify</CODE> statement.
<DT><CODE>recursion</CODE>
<DD>
-If <CODE>yes</CODE>, and a DNS query requests recursion, then the
+If <CODE>yes</CODE>, and a DNS query requests recursion, the
server will attempt to do all the work required to answer the query.
If recursion is not on, the server will return a referral to the
client if it doesn't know the answer. The default is <CODE>yes</CODE>.
See also <CODE>fetch-glue</CODE> above.
+
+<DT><CODE>rfc2308-type1</CODE>
+<DD>
+If <CODE>yes</CODE>, the server will send NS records along with the SOA
+record for negative answers.
+You need to set this to <CODE>no</CODE> if you have an old BIND
+server using you as a forwarder that does not understand negative answers
+which contain both SOA and NS records or you have an old version of sendmail.
+The correct fix is to upgrade the broken server or sendmail.
+The default is <CODE>no</CODE>.
+
+<DT><CODE>use-id-pool</CODE>
+<DD>
+If <CODE>yes</CODE>, the server will keep track of its own outstanding
+query ID's to avoid duplication and increase randomness. This will result
+in 128KB more memory being consumed by the server.
+The default is <CODE>no</CODE>.
+
+<DT><CODE>treat-cr-as-space</CODE>
+<DD>
+If <CODE>yes</CODE>, the server will treat '\r' characters the same way it
+treats a ' ' or '\t'. This may be necessary when loading zone files on a
+UNIX system that were generated on an NT or DOS machine. The default is <CODE>no</CODE>.
+
</DL>
-<H4>Forwarding</H4>
+<A NAME="Also-notify"><H4>Also-Notify</H4></A>
+
+<DT><CODE>also-notify</CODE>
+<P>
+Defines a global list of IP addresses that also get sent NOTIFY messages
+whenever a fresh copy of the zone is loaded. This helps to ensure that
+copies of the zones will quickly converge on ``stealth'' servers.
+If an <CODE>also-notify</CODE> list is given in a <CODE>zone</CODE>
+statement, it will override the <CODE>options also-notify</CODE> statement.
+When a <CODE>zone notify</CODE> statement is set to <CODE>no</CODE>,
+the IP addresses in the global <CODE>also-notify</CODE> list will not get
+sent NOTIFY messages for that zone.
+The default is the empty list (no global notification list).
+
+<A NAME="Forwarding"><H4>Forwarding</H4></A>
-<P>The forwarding facility can be used to create a large sitewide
+<P>The forwarding facility can be used to create a large site-wide
cache on a few servers, reducing traffic over links to external
nameservers. 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
@@ -197,6 +299,13 @@ Specifies the IP addresses to be used for forwarding. The default is the
empty list (no forwarding).
</DL>
+<P>Forwarding can also be configured on a per-zone basis, allowing for
+the global forwarding options to be overridden in a variety of ways.
+You can set particular zones to use different forwarders, or have
+different <CODE>forward only/first</CODE> behavior, or to not forward
+at all. See the <A HREF="zone.html"><CODE>zone</CODE></A> statement
+for more information.
+
<P>Future versions of BIND 8 will provide a more powerful forwarding
system. The syntax described above will continue to be supported.
@@ -239,7 +348,8 @@ client.
check-names response ignore;
</PRE>
-<P><CODE>check-names</CODE> may also be specified in the <CODE>zone</CODE>
+<P><CODE>check-names</CODE> may also be specified in the
+<A HREF="zone.html"><CODE>zone</CODE></A>
statement, in which case it overrides the <CODE>options check-names</CODE>
statement. When used in a <CODE>zone</CODE> statement, the area is not
specified (because it can be deduced from the zone type).
@@ -267,6 +377,18 @@ server. <CODE>allow-transfer</CODE> may also be specified in the
<CODE>zone</CODE> statement, in which case it overrides the
<CODE>options allow-transfer</CODE> statement. If not specified, the default
is to allow transfers from all hosts.
+
+<DT><CODE>allow-recursion</CODE>
+<DD>
+Specifies which hosts are allowed to make recursive queries through this
+server. If not specified, the default is to allow recursive queries from
+all hosts.
+
+<DT><CODE>blackhole</CODE>
+<DD>
+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.
</DL>
<H4>Interfaces</H4>
@@ -285,6 +407,10 @@ not specified, port 53 will be used.
listen-on port 1234 { !1.2.3.4; 1.2/16; };
</PRE>
+will enable the nameserver 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>If no <CODE>listen-on</CODE> is specified, the server will listen on port
53 on all interfaces.
@@ -321,7 +447,7 @@ The server supports two zone transfer methods.
<CODE>one-answer</CODE> uses one DNS message per resource record
transferred. <CODE>many-answers</CODE> packs as many resource records
as possible into a message. <CODE>many-answers</CODE> is more
-efficient, but is only known to be understood by BIND 8.1 and patched
+efficient, but is only known to be understood by BIND 8.1+ and patched
versions of BIND 4.9.5. The default is <CODE>one-answer</CODE>.
<CODE>transfer-format</CODE> may be
overridden on a per-server basis by using the <CODE>server</CODE> statement.
@@ -349,6 +475,36 @@ zones, but it also may increase the load on the remote nameserver.
<CODE>transfers-per-ns</CODE> may be overridden on a per-server basis
by using the <CODE>transfers</CODE> phrase of the <CODE>server</CODE>
statement.
+
+<DT><CODE>transfer-source</CODE>
+<DD>
+<CODE>transfer-source</CODE> determines which local address will be bound
+to the TCP connection used to fetch all zones transferred inbound by the
+server. 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 <CODE>allow-transfer</CODE>
+option for the zone being transferred, if one is specified. This statement
+sets the <CODE>transfer-source</CODE> for all zones, but can be overridden
+on a per-zone basis by including a <CODE>transfer-source</CODE> statement
+within the zone block in the configuration file.
+
+<DT><CODE>serial-queries</CODE>
+<DD>
+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, but more importantly each query uses a
+small amount of <I>memory</I> in the slave server while waiting for the
+master server to respond. The <CODE>serial-queries</CODE> option sets the
+maximum number of concurrent serial-number queries allowed to be outstanding
+at any given time. The default is four (4).
+<B>Note:</B>
+If a server loads a large (tens or hundreds of thousands) number of slave
+zones, this limit should be raised to the high hundreds or low
+thousands -- otherwise the slave server may never actually become aware of
+zone changes in the master servers. Beware, though, that setting this limit
+arbitrarily high can spend a considerable amount of your slave server's
+network, CPU, and memory resources. As with all tunable limits, this one
+should be changed gently and monitored for its effects.
</DL>
<H4>Resource Limits</H4>
@@ -366,7 +522,7 @@ example, <CODE>1G</CODE> can be used instead of
<CODE>unlimited</CODE> requests unlimited use, or the maximum
available amount. <CODE>default</CODE> uses the limit that was in
force when the server was started. See
-<VAR><AHREF="docdef.html">size_spec</A></VAR> for more details.
+<VAR><A HREF="docdef.html">size_spec</A></VAR> for more details.
<DL>
<DT><CODE>coresize</CODE>
@@ -380,7 +536,7 @@ The maximum amount of data memory the server may use. The default is
<DT><CODE>files</CODE>
<DD>
-The maximum number of files ther server may have open concurrently.
+The maximum number of files the server may have open concurrently.
The default is <CODE>unlimited</CODE>. <I>Note:</I> on some operating
systems the server cannot set an unlimited value and cannot determine
the maximum number of open files the kernel can support. On such
@@ -390,6 +546,12 @@ and the value returned by <CODE>sysconf(_SC_OPEN_MAX)</CODE>. If the
actual kernel limit is larger than this value, use <CODE>limit
files</CODE> to specify the limit explicitly.
+<DT><CODE>max-ixfr-log-size</CODE>
+<DD>
+The <CODE>max-ixfr-log-size</CODE> will be used in a future release of
+the server to limit the size of the
+transaction log kept for Incremental Zone Transfer.
+
<DT><CODE>stacksize</CODE>
<DD>
The maximum amount of stack memory the server may use. The default is
@@ -405,6 +567,12 @@ The server will remove expired resource records from the cache every
<CODE>cleaning-interval</CODE> minutes. The default is 60 minutes. If set
to 0, no periodic cleaning will occur.
+<DT><CODE>heartbeat-interval</CODE>
+<DD>
+The server will perform zone maintenance tasks for all zones marked
+<CODE>dialup yes</CODE> whenever this interval expires.
+The default is 60 minutes. Reasonable values are up to 1 day (1440 minutes).
+If set to 0, no zone maintenance for these zones will occur.
<DT><CODE>interface-interval</CODE>
<DD>
The server will scan the network interface list every
@@ -417,11 +585,11 @@ cleaned up.
<DT><CODE>statistics-interval</CODE>
<DD>
-Nameserver statisitics will be logged every <CODE>statistics-interval</CODE>
+Nameserver statistics will be logged every <CODE>statistics-interval</CODE>
minutes. The default is 60. If set to 0, no statistics will be logged.
</DL>
-<H4>Topology</H4>
+<H4><A NAME="topology">Topology</A></H4>
<P>All other things being equal, when the server chooses a nameserver
to query from a list of nameservers, it prefers the one that is
@@ -455,15 +623,192 @@ of all.
topology { localhost; localnets; };
</PRE>
+<H4><A NAME="sortlist">Resource Record sorting</A></H4>
+
+<P>
+When returning multiple RRs,
+the nameserver will normally return them in
+<B>Round Robin</B>,
+i.e. after each request, the first RR is put to the end of the list.
+As the order of RRs is not defined, this should not cause any problems.
+</P>
+<P>
+The client resolver code should re-arrange the RRs as appropriate,
+i.e. using any addresses on the local net in preference to other addresses.
+However, not all resolvers can do this, or are not correctly configured.
+</P>
+<P>
+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 nameservers, not all the clients.
+</P>
+<P>
+The sortlist statement takes an address match list and interprets it even
+more specially than the <A HREF="#topology">topology</A> statement does.
+</P>
+<P>
+Each top level statement in the sortlist must itself be an explicit
+address match list with one or two elements. The first element
+(which may be an IP address, an IP prefix, an ACL name or nested
+address match list) 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, the second element is treated like the address
+match list in a topology 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.
+<PRE>
+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>
+The following example will give reasonable behaviour for the local host
+and hosts on directly connected networks. It is similar to the behavior
+of the address sort in BIND 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.
+<PRE>
+sortlist {
+ { localhost; localnets; };
+ { localnets; };
+};
+</PRE>
+<!--
+ * XXX - it would be nice to have an ACL called "source" that matched the
+ * source address of a query so that a host could be configured to
+ * automatically prefer itself, and an ACL called "sourcenet", that
+ * would return the primitive IP match element that matched the source
+ * address so that you could do:
+ * { localnets; { sourcenet; { other stuff ...}; };
+ * and automatically get similar behaviour to what you get with:
+ * { localnets; };
+-->
+</P>
+
+<a name="RrsetOrder">
+<H4>RRset Ordering</H4>
+
+<P>When multiple records are returned in an answer it may be useful to
+configure the order the records are placed into the response. For example the
+records for a zone might be configured to always be returned in the order they
+are defined in the zone file. Or perhaps a <i>random</i> shuffle of the
+records as they are returned is wanted. The <var>rrset-order</var> statement
+permits configuration of the ordering made of the records in a multiple record
+response. The default, if no ordering is defined, is a cyclic ordering (round
+robin).
+
+<P>An <var>order_spec</var> is defined as follows:
+
+<PRE>
+ [ <var>class</var> class_name ][ <var>type</var> type_name ][ <var>name</var> "FQDN" ] <var>order</var> ordering
+</PRE>
+
+<P>If no <var>class</var> is specified, the default is <code>ANY</code>. If no
+<var>type</var> is specified, the default is <code>ANY</code>. If no
+<var>name</var> is specified, the default is <code>"*"</code>.
+
+<P>The legal values for <code>ordering</code> are:
+
+<DL>
+<DT><code>fixed</code>
+<DD>Records are returned in the order they are defined in the zone file.
+
+<DT><code>random</code>
+<DD>Records are returned in some random order.
+
+<DT><code>cyclic</code>
+<DD>Records are returned in a round-robin order.
+
+</DL>
+
+
+<P>For example:
+
+<PRE>
+ rrset-order {
+ class IN type A name "rc.vix.com" order random;
+ order cyclic;
+ };
+</PRE>
+
+<P>will cause any responses for type <VAR>A</VAR> records in class
+<VAR>IN</VAR> that have "rc.vix.com" as a suffix, to always be returned in
+random order. All other records are returned in cyclic order.
+
+<P>If multiple <code>rrset-order</code> statements appear, they are not
+combined--the last one applies.
+
+<P>If no <code>rrset-order</code> statement is specified, a default one
+of:
+
+<pre>
+ rrset-order { class ANY type ANY name "*" order cyclic ; };
+</pre>
+
+<P>is used.
+
+<H4>Tuning</H4>
+
+<DL>
+<DT><CODE>lame-ttl</CODE>
+<DD>
+Sets the number of seconds to cache a lame server indication.
+0 disables caching. Default is 600 (10 minutes). Maximum value is 1800 (30 minutes).
+<DT><CODE>max-ncache-ttl</CODE>
+<DD>
+To reduce network traffic and increase performance the server stores negative
+answers. <CODE>max-ncache-ttl</CODE> is used to set a maximum retention time
+for these answers in the server is seconds. The default <CODE>max-ncache-ttl</CODE> is
+10800 seconds (3 hours). <CODE>max-ncache-ttl</CODE> cannot exceed the
+maximum retention time for ordinary (positive) answers (7 days) and will be
+silently truncated to 7 days if set to a value which is greater that 7 days.
+<DT><CODE>min-roots</CODE>
+<DD>
+The minimum number of root servers that is required for a
+request for the root servers to be accepted. Default 2.
+</DL>
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+Last Updated: $Id: options.html,v 1.36 1999/10/13 20:57:05 cyarnell Exp $
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