Title: Building Firewalls with OpenBSD and PF, 2nd ed.
Author: Jacek Artymiak
pages: 336
Written by Jacek Artymiak, a frequent contributor to ONLamp.com, Building Firewalls with OpenBSD and PF is the first and only print publication devoted solely to the subject of the pf packet filter used in OpenBSD, FreeBSD, and NetBSD operating systems. Topics covered include: firewall design, ruleset syntax, packet normalization (scrubbing), packet redirection (masquerading), packet filtering, bandwidth management (ALTQ), load balancing, and more.
Jacek Artymiak has been working with Unix systems since 1991. He has written books on other Unix-class systems and is a frequent contributor to the O'Reilly Networks sites, where he often writes about OpenBSD and PF.