- bgpmon_filter - Critical Prefix Filter
- BGPmon::Filter - This module provides information of if a BGP message matches a set of IPv4 or IPv6 prefixes, or if it matches a specific autonymous system number.
- BGPmon::Filter::Address - This module is an object that keeps track of an IPv4 or IPv6 address. It can compare two a prefix to itself to see if it belongs to that prefix.
- BGPmon::Filter::Prefix - This module is an object that keeps track of an IPv4 or IPv6 prefix. It can compare two different prefixes and find if they're equivilent, if one is more specific than the other, or if one is less specific than the other.