RESOLVER

Section: File Formats (5)
Updated: September 14, 1987
Index Return to Main Contents

NAME

resolver - resolver configuration file

SYNOPSIS

/etc/resolv.conf

DESCRIPTION

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 name-value pairs 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 and the domain name is retrieved from the system.

The different configuration options are:

nameserver: followed by the Internet address (in dot notation) of a name server that the resolver should query. At least one name server should be listed. Up to MAXNS (currently 3) name servers may be listed, in that case the resolver library queries tries 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: followed by a domain name, that is the default domain to append to names that do not have a dot in them. If no domain entries are present, the domain returned by gethostname(2) is used (everything after the first `.'). Finally, if the host name does not contain a domain part, the root domain is assumed.

The name value pair 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