Block spammers/abusive IPs with Pf-badhost in OpenBSD. A 'must have' security tool!
by from OpenBSD Journal on (#5D107)
Introduction
Pf-badhostis a very practical, robust, stable and lightweight security script for network servers.
It's compatible with BSD based operating systems such as {Open,Free,Net,Dragonfly}BSD and MacOS. It prevents potentially-bad IP addresses that could possibly attack your servers (and waste your bandwidth and fill your logfiles), by blocking all those IPs contacting your server, and therefore it makes your server network/resources lighter and the logs of important services running on your server become simpler, more readable and efficient.