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diff --git a/contrib/bind/doc/man/resolver.5 b/contrib/bind/doc/man/resolver.5 new file mode 100644 index 0000000..044bf60 --- /dev/null +++ b/contrib/bind/doc/man/resolver.5 @@ -0,0 +1,183 @@ +.\" Copyright (c) 1986 The Regents of the University of California. +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms are permitted +.\" provided that the above copyright notice and this paragraph are +.\" duplicated in all such forms and that any documentation, +.\" advertising materials, and other materials related to such +.\" distribution and use acknowledge that the software was developed +.\" by the University of California, Berkeley. The name of the +.\" University may not be used to endorse or promote products derived +.\" from this software without specific prior written permission. +.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR +.\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED +.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. +.\" +.\" @(#)resolver.5 5.9 (Berkeley) 12/14/89 +.\" $Id: resolver.5,v 8.4 1997/03/14 02:29:49 vixie Exp $ +.\" +.Dd November 11, 1993 +.Dt RESOLVER @FORMAT_EXT_U@ +.Os BSD 4 +.Sh NAME +.Nm resolver +.Nd resolver configuration file +.Sh SYNOPSIS +.Pa /etc/resolv.conf +.Sh DESCRIPTION +The +.Nm resolver +is a set of routines in the C library +.Pq Xr resolve @LIB_NETWORK_EXT@ +that provide access to the Internet Domain Name System. +The +.Nm resolver +configuration file contains information that is read +by the +.Nm resolver +routines the first time they are invoked by a process. +The file is designed to be human readable and contains a list of +keywords with values that provide various types of +.Nm resolver +information. +.Pp +On a normally configured system, this file should not be necessary. +The only name server to be queried will be on the local machine, +the domain name is determined from the host name, +and the domain search path is constructed from the domain name. +.Pp +The different configuration options are: +.Bl -tag -width "nameser" +.It Li nameserver +Internet address (in dot notation) of a name server that the +.Nm resolver +should query. Up to +.Dv MAXNS +(currently 3) name servers may be listed, one per keyword. +If there are multiple servers, the +.Nm resolver +library queries them in the order listed. +If no +.Li nameserver +entries are present, the default is to use the name server on the local machine. +(The algorithm used is to try a name server, and if the query times out, +try the next, until out of name servers, +then repeat trying all the name servers +until a maximum number of retries are made). +.It Li domain +Local domain name. +Most queries for names within this domain can use short names +relative to the local domain. +If no +.Li domain +entry is present, the domain is determined from the local host name returned by +.Xr gethostname @BSD_SYSCALL_EXT@ ; +the domain part is taken to be everything after the first +.Sq \&. . +Finally, if the host name does not contain a domain part, the root +domain is assumed. +.It Li search +Search list for host-name lookup. +The search list is normally determined from the local domain name; +by default, it contains only the local domain name. +This may be changed by listing the desired domain search path +following the +.Li search +keyword with spaces or tabs separating the names. +Most +.Nm resolver +queries will be attempted using each component +of the search path in turn until a match is found. +Note that this process may be slow and will generate a lot of network +traffic if the servers for the listed domains are not local, +and that queries will time out if no server is available +for one of the domains. +.Pp +The search list is currently limited to six domains +with a total of 256 characters. +.It Li sortlist +Allows addresses returned by gethostbyname to be sorted. +A +.Li sortlist +is specified by IP address netmask pairs. The netmask is +optional and defaults to the natural netmask of the net. The IP address +and optional network pairs are separated by slashes. Up to 10 pairs may +be specified. For example: +.Bd -literal -offset indent +sortlist 130.155.160.0/255.255.240.0 130.155.0.0 +.Ed +.It Li options +Allows certain internal +.Nm resolver +variables to be modified. +The syntax is +.D1 Li options Ar option ... +where +.Ar option +is one of the following: +.Bl -tag -width "ndots:n " +.It Li debug +sets +.Dv RES_DEBUG +in +.Ft _res.options . +.It Li ndots: Ns Ar n +sets a threshold for the number of dots which +must appear in a name given to +.Fn res_query +(see +.Xr resolver @LIB_NETWORK_EXT@ ) +before an +.Em initial absolute query +will be made. The default for +.Ar n +is +.Dq 1 , +meaning that if there are +.Em any +dots in a name, the name will be tried first as an absolute name before any +.Em search list +elements are appended to it. +.El +.El +.Pp +The +.Li domain +and +.Li search +keywords are mutually exclusive. +If more than one instance of these keywords is present, +the last instance wins. +.Pp +The +.Li search +keyword of a system's +.Pa resolv.conf +file can be +overridden on a per-process basis by setting the environment variable +.Dq Ev LOCALDOMAIN +to a space-separated list of search domains. +.Pp +The +.Li options +keyword of a system's +.Pa resolv.conf +file can be amended on a per-process basis by setting the environment variable +.Dq Ev RES_OPTIONS to a space-separated list of +.Nm resolver +options as explained above under +.Li options . +.Pp +The keyword and value must appear on a single line, and the keyword +(e.g., +.Li nameserver ) +must start the line. The value follows the keyword, separated by white space. +.Sh FILES +.Pa /etc/resolv.conf +.Sh SEE ALSO +.Xr gethostbyname @LIB_NETWORK_EXT@ , +.Xr hostname @DESC_EXT@ , +.Xr @INDOT@named @SYS_OPS_EXT@ , +.Xr resolver @LIB_NETWORK_EXT@ , +.Xr resolver @FORMAT_EXT@ . +.Dq Name Server Operations Guide for Sy BIND |