This module provides functions to deal with IPv4/IPv6 addresses.  The
module can be used as a class, allowing the user to instantiate IP
objects, which can be single IP addresses, prefixes, or ranges of
addresses.  There is also a procedural way of accessing most of the
functions.  Most subroutines can take either IPv4 or IPv6 addresses
transparently.

WWW: http://search.cpan.org/dist/Net-IP/