OpenBSD PF: Filtering traffic by Operating System
I was reading through the PF manual, and came across a section on filtering traffic with “Passive Operating System Fingerprinting”: http://www.openbsd.org/faq/pf/filter.html PF contains dozens of Operating System fingerprints. The full list of fingerprints can be printed with the pfctl utility: $ pfctl -s osfp | tail -5 Windows XP RFC1323 Windows XP SP1 Windows XP [...]
