The dnsutl package is a bunch of	programs I wrote to make
       using DNS easier.  These	include:

       dns-rev
	       Take the	forward	DNS mapping and	generate the
	       reverse mapping.

       dns-hosts
	       Take the	forward	DNS mapping and	generate the
	       /etc/hosts file.

       dns-ng
	       Take the	forward	DNS mapping and	generate the
	       /etc/netgroup file.

       All of these programs are both faster than shell	scripts,
       and more	robust when faced with all the peculiar	semantics
       of DNS resource files.

WWW: http://www.canb.auug.org.au/~millerp/dnsutl/