resolver
Hurricane Electric Internet Services
NAME
resolver - resolver configuration file
SYNOPSIS
/etc/resolv.conf
DESCRIPTION
The resolver is a set of routines in the C library
(resolv(3)) that provide access to the Internet Domain
Name System. The resolver configuration file contains
information that is read by the resolver routines the
first time they are invoked by a process. The file is
designed to be human readable and contains a list of key-
words with values that provide various types of resolver
information.
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.
The different configuration options are:
nameserver
Internet address (in dot notation) of a name server
that the resolver should query. Up to MAXNS (cur-
rently 3) name servers may be listed, one per key-
word. If there are multiple servers, the resolver
library queries them in the order listed. If no
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).
domain Local domain name. Most queries for names within
this domain can use short names relative to the
local domain. If no domain entry is present, the
domain is determined from the local host name
returned by gethostname(2); the domain part is
taken to be everything after the first `.'.
Finally, if the host name does not contain a domain
part, the root domain is assumed.
search Search list for host-name lookup. The search list
is normally determined from the local domain name;
by default, it begins with the local domain name,
then successive parent domains that have at least
two components in their names. This may be changed
by listing the desired domain search path following
the search keyword with spaces or tabs separating
the names. Most 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.
The search list is currently limited to six domains
with a total of 256 characters.
The domain and search keywords are mutually exclusive. If
more than one instance of these keywords is present, the
last instance will override.
The keyword and value must appear on a single line, and
the keyword (e.g. nameserver) must start the line. The
value follows the keyword, separated by white space.
FILES
/etc/resolv.conf
SEE ALSO
gethostbyname(3N), resolver(3), hostname(7), named(8)
Name Server Operations Guide for BIND
Hurricane Electric Internet Services
Copyright (C) 1998
Hurricane Electric.
All Rights Reserved.