# The Book of PF by Peter N. M. Hansteen

5 Hacker News commenters recommended The Book of PF by Peter N. M. Hansteen and 0 criticized it, November 2025 to November 2026. It was recommended in 3 of 13 months.

**Verdict:** Recommended as a practical introduction to PF, the packet filter, that helps readers learn how firewalls operate and which rules to write.

## Why people recommend it

- Explains how firewalls operate (1 comments): "this should give you enough insight on how a firewall operates to get a sense of what rules to write" ([source](https://news.ycombinator.com/item?id=48229522))
- Good starting point for beginners (1 comments): "it helps to start in the shallow end before you tread into deeper waters" ([source](https://news.ycombinator.com/item?id=46845310))
- Valuable and helped professionally (2 comments): "It's a great book, I used to have some edition of it and it helped me a lot professionally" ([source](https://news.ycombinator.com/item?id=46845002)) "I think these books are very valuable." ([source](https://news.ycombinator.com/item?id=46847275))

## Alternatives hackers recommend

- [TCP/IP Illustrated by W. Richard Stevens](https://hackerapproved.com/p/tcp-ip-illustrated.md): 7 recommend
- [High-Performance Browser Networking by Ilya Grigorik](https://hackerapproved.com/p/high-performance-browser-networking.md): 4 recommend

## Where to get it

- [See price on Amazon](https://www.amazon.com/dp/1718504705?tag=hackerapprove-20) (affiliate link)
- [Bookshop.org](https://bookshop.org/a/130825/9781718504707) (affiliate link)

## Cite as

Hacker Approved, "The Book of PF by Peter N. M. Hansteen", https://hackerapproved.com/p/book-of-pf-4th-edition/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).