Domain Names

A domain name is the name assigned to a group of systems on a local network that share DNS administrative files. A domain name is required for the network information service database to work properly.

Default Domain Name

DNS obtains your default domain name from your resolv.conf file.

• If the resolv.conf file is not available, or does not identify a default domain, and if your enterprise-level name service is either NIS+ or NIS, the Sun implementation of DNS obtains the default domain name from those services.

• If resolv.conf is not available or does not provide a domain name and you are not running either NIS+ or NIS, you must either provide a resolv.conf file on each machine that does specify the domain (see "The Resolver"), or set the LOCALDOMAIN environment variable.

Trailing Dots in Domain Names

When working with DNS-related files, follow these rules regarding the trailing dot in domain names:

• Use a trailing dot in domain names in hosts, hosts.rev, named.ca, and named.local data files. For example, sales.doc.com. is correct for these files.

• Do not use a trailing dot in domain names in named.boot or resolv.conf files. For example, sales.doc.com is correct for these files.