The resolver configuration file contains information that is read by the resolver routines the first time they are invoked in a process. The file is designed to be human readable and contains a list of name-value pairs which provide various types of resolver information.
The different configuration options are:
nameserver followed by the Internet address (in dot notation) of a nameserver that the resolver should query. At least one nameserver should be listed. Up to MAXNS (currently 3) nameservers may be listed, in which case the resolver library queries tries them in the order listed. (The algorithm used is to try a nameserver, and if the query times out, try the next, until out of nameservers, then repeat trying all the nameservers until a maximum number of retries has been made).
domain followed by a domain name, which is the default domain to append to names which do not have a dot in them. This defaults to empty (the root domain).
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 whitespace.
There is currently no way to indicate that one address for a host is preferred over another. (Solutions are being considered).