The Resolver Library

When talking of ``the resolver'', we do not mean any special application, but rather refer to the resolver library, a collection of functions that can be found in the standard C library. The central routines are gethostbyname(2) and gethostbyaddr(2) which look up all IP addresses belonging to a host, and vice versa. They may be configured to simply look up the information in hosts, query a number of name servers, or use the hosts database of NIS (Network Information Service). Other applications, like smail, may include different drivers for any of these, and need special care.

• The host.conf File
• Resolver Environment Variables
• Configuring Name Server Lookups-- resolv.conf
• Resolver Robustness