Internal Program Version: NetAddr::IP  4.079

This module provides an object-oriented abstraction on top of 
IP addresses or IP subnets that allows for easy manipulations. 
Version 4.xx of NetAddr::IP will work with older versions of Perl
and is compatible with Math::BigInt.

The internal representation of all IP objects is in 128 bit IPv6 
notation. IPv4 and IPv6 objects may be freely mixed.

http://search.cpan.org/dist/NetAddr-IP