Peter N. M. Hansteen is a consultant, writer and sysadmin based in Bergen, Norway. A longtime Freenix advocate, Hansteen is a frequent lecturer on FreeBSD and OpenBSD topics. His expertise as a documentation consultant (and humorous work with the RFC 1149 implementation team) have helped him gain regard in Norwegian IT publications. The Book of PF, Hansteen's first book, is an expanded follow-up to his very popular online PF tutorial.
"All in all, this book is very readable and a must-have resource for anyone who deals with firewall configurations. If you've heard good things about PF and have been thinking of giving it a go, this book is definitely for you. Start at the beginning and before you know it you'll be through the book and quite the PF guru. Even if you're already a PF guru, this is still a good book to keep on the shelf to refer to in thorny situations or to lend to colleagues."
--Dru Lavigne, Technical Writer
"This book should be in any well-stocked bookshelf."
--Axel Gruner, BSDWiki