OpenBSD's stateful packet filter, PF, offers an amazing feature set and support across the major BSD platforms. Like most firewall software though, unlocking PF's full potential takes a good teacher. Peter N.M. Hansteen's PF website and conference tutorials have helped thousands of users build the networks they need using PF. The Book of PF is the product of Hansteen's knowledge and experience, teaching good practices as well as bare facts and software options. Throughout the book, Hansteen emphasizes the importance of staying in control by having a written network specification, using macros to make rule sets more readable, and performing rigid testing when loading in new rules. Today's system administrators face increasing challenges in the quest for network quality, and The Book of PF can help by demystifying the tools of modern *BSD network defense. But, perhaps more importantly, because we know you like to tinker, The Book of PF tackles a broad range of topics that will stimulate your mind and pad your resume, including how to: Create rule sets for all kinds of network traffic, whether it is crossing a simple home LAN, hiding behind NAT, traversing DMZs, or spanning bridges Use PF to create a wireless access point, and lock it down tight with authpf and special access restrictions Maximize availability by using redirection rules for load balancing and CARP for failover Use tables for proactive defense against would-be attackers and spammers Set up queues and traffic shaping with ALTQ, so your network stays responsive Master your logs with monitoring and visualization, because you can never be too paranoid The Book of PF is written for BSD enthusiasts and network admins at any level of expertise. With more and more services placing high demands on bandwidth and increasing hostility coming from the Internet at-large, you can never be too skilled with PF.