Commit | Line | Data |
---|---|---|
d58c18e3 KB |
1 | .\" Copyright (c) 1986 The Regents of the University of California. |
2 | .\" All rights reserved. | |
ba305536 | 3 | .\" |
d58c18e3 KB |
4 | .\" Redistribution and use in source and binary forms are permitted |
5 | .\" provided that the above copyright notice and this paragraph are | |
6 | .\" duplicated in all such forms and that any documentation, | |
7 | .\" advertising materials, and other materials related to such | |
8 | .\" distribution and use acknowledge that the software was developed | |
9 | .\" by the University of California, Berkeley. The name of the | |
10 | .\" University may not be used to endorse or promote products derived | |
11 | .\" from this software without specific prior written permission. | |
12 | .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
13 | .\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
14 | .\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
15 | .\" | |
e91b6c79 | 16 | .\" @(#)resolver.5 5.8 (Berkeley) %G% |
56b0d82b JB |
17 | .\" |
18 | .TH RESOLVER 5 "" | |
ba305536 KD |
19 | .UC 4 |
20 | .SH NAME | |
d09d27e2 | 21 | resolver \- resolver configuration file |
56b0d82b JB |
22 | .SH SYNOPSIS |
23 | /etc/resolv.conf | |
ba305536 KD |
24 | .SH DESCRIPTION |
25 | .LP | |
e91b6c79 MK |
26 | The |
27 | .I resolver | |
28 | is a set of routines in the C library (\c | |
29 | .IR resolv (3)) | |
30 | that provide access to the Internet Domain Name System. | |
ba305536 | 31 | The resolver configuration file contains information that is read |
56b0d82b | 32 | by the resolver routines the first time they are invoked by a process. |
ba305536 | 33 | The file is designed to be human readable and contains a list of |
e91b6c79 | 34 | keywords with values that provide various types of resolver information. |
ba305536 | 35 | .LP |
56b0d82b | 36 | On a normally configured system this file should not be necessary. |
e91b6c79 MK |
37 | The only name server to be queried will be on the local machine, |
38 | the domain name is determined from the host name, | |
39 | and the domain search path is constructed from the domain name. | |
56b0d82b | 40 | .LP |
ba305536 KD |
41 | The different configuration options are: |
42 | .TP | |
43 | \fBnameserver\fP | |
e91b6c79 MK |
44 | Internet address (in dot notation) of a name server |
45 | that the resolver should query. | |
46 | Up to MAXNS (currently 3) name servers may be listed, | |
47 | one per keyword. | |
48 | If there are multiple servers, | |
49 | the resolver library queries them in the order listed. | |
56b0d82b JB |
50 | If no \fBnameserver\fP entries are present, |
51 | the default is to use the name server on the local machine. | |
e925f881 | 52 | (The algorithm used is to try a name server, and if the query times out, |
56b0d82b JB |
53 | try the next, until out of name servers, |
54 | then repeat trying all the name servers | |
e925f881 | 55 | until a maximum number of retries are made). |
ba305536 KD |
56 | .TP |
57 | \fBdomain\fP | |
e91b6c79 MK |
58 | Local domain name. |
59 | Most queries for names within this domain can use short names | |
60 | relative to the local domain. | |
61 | If no \fBdomain\fP entry is present, the domain is determined | |
62 | from the local host name returned by | |
63 | \fIgethostname\fP\|(2); | |
64 | the domain part is taken to be everything after the first `.'. | |
56b0d82b JB |
65 | Finally, if the host name does not contain a domain part, the root |
66 | domain is assumed. | |
e91b6c79 MK |
67 | .TP |
68 | \fBsearch\fP | |
69 | Search list for host-name lookup. | |
70 | The search list is normally determined from the local domain name; | |
71 | by default, it begins with the local domain name, then successive | |
72 | parent domains that have at least two components in their names. | |
73 | This may be changed by listing the desired domain search path | |
74 | following the \fIsearch\fP keyword with spaces or tabs separating | |
75 | the names. | |
76 | Most resolver queries will be attempted using each component | |
77 | of the search path in turn until a match is found. | |
78 | Note that this process may be slow and will generate a lot of network | |
79 | traffic if the servers for the listed domains are not local, | |
80 | and that queries will time out if no server is available | |
81 | for one of the domains. | |
82 | .LP | |
83 | The \fIdomain\fP and \fIsearch\fP keywords are mutually exclusive. | |
84 | If more than one instance of these keywords is present, | |
85 | the last instance will override. | |
ba305536 | 86 | .LP |
e91b6c79 | 87 | The keyword and value must appear on a single line, and the keyword |
ba305536 | 88 | (e.g. \fBnameserver\fP) must start the line. The value follows |
e925f881 | 89 | the keyword, separated by white space. |
ba305536 KD |
90 | .SH FILES |
91 | .I /etc/resolv.conf | |
92 | .SH SEE ALSO | |
e91b6c79 | 93 | gethostbyname(3N), resolver(3), hostname(7), named(8) |
56b0d82b JB |
94 | .br |
95 | Name Server Operations Guide for BIND |