IPA_IPFW -- IPA accounting module for FreeBSD IP Firewall

Main features:

- The module is designed for traffic accounting from IP Firewall
  (including IPFW2) rules byte counters;
- The module understands IP Firewall rules byte counters overflow;
- It is possible to summarize and subtract statistics of IP Firewall
  rules byte counters;
- It is possible to distinguish IP Firewall rules with the same numbers;
- IP Firewall rules can be dynamically added to and deleted from
  the system, the module correctly works in such situations.

WWW: http://ipa-system.sourceforge.net/modules/ipa_ipfw/