12.4 Configuring DNS

DNS maps hostnames to IP addresses and vice versa. Configuring DNS can be somewhat difficult. However, you can easily configure your Linux system as a caching name server. A caching name server remembers mappings it has recently fetched and can supply them to clients. Accessing a local or nearby caching name server is much faster than accessing a remote name server.

The Linux program that performs name resolution is the Berkeley Internet Name Daemon (BIND). BIND is sometimes referred to as named (pronounced name dee), an abbreviation for name daemon. So, the same facility is variously referred to as DNS, BIND, or named. Some Linux/Unix systems are configured to use a name server other than BIND; however, BIND is the most popular name server on the Internet.

To install BIND and configure it as a caching name server, use the Package Mangement Tool to install the DNS Name Server package group and the extra package caching-nameserver.

To start the named service, use the Service Configuration Tool. You can also use the Tool to associate the service with one or more runlevels.

To use the named server, you must specify its IP address in the resolver configuration. To do so, launch the Network Administration Tool. Make a record of the existing specification and then specify 127.0.0.1 as the IP address of the primary name server. Test your name server by pinging an Internet host:

ping www.ora.com

A series of replies confirms that the name server is working. Press Ctrl-C to halt the pinging.