libnet-netmask-perl

Net::Netmask parses and understands IPv4 and IPv6 CIDR blocks (see https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing for more information on CIDR blocks). It's built with an object-oriented interface, with functions being methods that operate on a Net::Netmask object. These methods provide nearly all types of information about a network block that you might want. There are also functions to insert a network block into a table and then later lookup network blocks by IP address using that table. There are functions to turn a IP address range into a list of CIDR blocks. There are functions to turn a list of CIDR blocks into a list of IP addresses. There is a function for sorting by text IP address. All functions understand both IPv4 and IPv6. Matches, finds, etc, will always return false when an IPv4 address is matched against an IPv6 address. IPv6 support was added in 1.9104.