Yes, You Too Can Be An Evil Network Overlord - On The Cheap With OpenBSD, pflow And nfsen https://nxdomain.no/~peter/yes_you_too_can_be_an_evil_network_verlord.html

A story about network metadata and #openbsd, originally from 2014, good for reprising. See The Book of PF for more #nfsen #netflow #pflow #monitoring #networking #security #pf #packetfilter #bookofPF @nostarch

Yes, You Too Can Be An Evil Network Overlord - On The Cheap With OpenBSD, pflow And nfsen https://nxdomain.no/~peter/yes_you_too_can_be_an_evil_network_verlord.html

A story about network metadata and #openbsd, originally from 2014, good for reprising. See The Book of PF for more #nfsen #netflow #pflow #monitoring #networking #security #pf #packetfilter #bookofPF @nostarch

Friends, is this https://nxdomain.no/~peter/20260224_smtp_blast_to_imaginary_friends.txt what a successful campaign looks like?

(also see https://nxdomain.no/~peter/eighteen_years_of_greytrapping.html or for that matter https://nostarch.com/book-of-pf-4e) @nostarch #greyptrapping #spam #spamd #pf #packetfilter #greylisting #email #cybercrime #marketing #scams

Friends, is this https://nxdomain.no/~peter/20260224_smtp_blast_to_imaginary_friends.txt what a successful campaign looks like?

(also see https://nxdomain.no/~peter/eighteen_years_of_greytrapping.html or for that matter https://nostarch.com/book-of-pf-4e) @nostarch #greyptrapping #spam #spamd #pf #packetfilter #greylisting #email #cybercrime #marketing #scams

I just wrapped up an interesting call that was originally scheduled for last week but rescheduled for today. The client is looking for a unique setup, and thanks to having an early re-read of the fantastic The Book of PF - 4th Edition, I was able to propose some configurations that had completely slipped my mind. The client is extremely curious, and this will likely lead to a new OpenBSD deployment in an interesting environment.

At the same time, I received an email from a professor at an Italian university whom I had encouraged to extend his lectures to include BSDs. I piqued his curiosity as well and proposed a session specifically on firewalls, focusing on OpenBSD and pf. He will be reading The Book of PF soon and will likely add it to his students' recommended reading list. I'll probably present them, too.

In short - one book, a thousand new possibilities. Infinite thanks to @pitrh for the massive and wonderful work behind it.

https://nostarch.com/book-of-pf-4th-edition

#OpenBSD #FreeBSD #NetBSD #RunBSD #PF #Firewalling #IT #SysAdmin

The fresh 4th edition of The Book of PF in physical form has reached Europe (Ireland), https://www.linkedin.com/posts/tomsmythconnect_thebookofpf-openbsd-packetfilter-activity-7427686906349555713-7s4w - so my stack of author copies are hopefully on the way too.

The book home page is at https://nostarch.com/book-of-pf-4th-edition

Some background https://nxdomain.no/~peter/yes_the_book_of_pf_4th_ed_is_coming.html @nostarch #bookofpf #openbsd #freebsd #pf #packetfilter #networking #security

The fresh 4th edition of The Book of PF in physical form has reached Europe (Ireland), https://www.linkedin.com/posts/tomsmythconnect_thebookofpf-openbsd-packetfilter-activity-7427686906349555713-7s4w - so my stack of author copies are hopefully on the way too.

The book home page is at https://nostarch.com/book-of-pf-4th-edition

Some background https://nxdomain.no/~peter/yes_the_book_of_pf_4th_ed_is_coming.html @nostarch #bookofpf #openbsd #freebsd #pf #packetfilter #networking #security

This little sketchbook drawing is to celebrate my successful completion of setting up OpenBSD as a gateway, DNS host, NAT router, and packet filter with pf. I'm working slowly and making sure I understand each step. Very happy with it so far.

#openBsd #pf

This little sketchbook drawing is to celebrate my successful completion of setting up OpenBSD as a gateway, DNS host, NAT router, and packet filter with pf. I'm working slowly and making sure I understand each step. Very happy with it so far.

#openBsd #pf

I bought a copy of "The Book of PF" from @pitrh

It's the best and most comprehensive resource about the marvelous PF firewall that I've ever seen, and I've been using PF since the early days.

Amazing work!

It's available here on No Starch Press: https://nostarch.com/book-of-pf-4th-edition

I also recently wrote a practical guide on PF (https://blog.hofstede.it/pf-firewall-on-freebsd-a-practical-guide/) for anyone who wants to get started :-)

#freebsd #pf #networking #firewall #books

I bought a copy of "The Book of PF" from @pitrh

It's the best and most comprehensive resource about the marvelous PF firewall that I've ever seen, and I've been using PF since the early days.

Amazing work!

It's available here on No Starch Press: https://nostarch.com/book-of-pf-4th-edition

I also recently wrote a practical guide on PF (https://blog.hofstede.it/pf-firewall-on-freebsd-a-practical-guide/) for anyone who wants to get started :-)

#freebsd #pf #networking #firewall #books

Upcoming "Network Management with the OpenBSD Packet Filter Toolset" tutorials (covering #freebsd and #openbsd):

2026-03-19 AsiaBSDCob https://www.asiabsdcon.org
2026-06-18 BSDCan https://www.bsdcan.org

See https://nxdomain.no/~peter/pf_tutorial_upcoming_questions_welcome.html (https://bsdly.blogspot.com/2025/05/for-upcoming-pf-tutorials-we-welcome.html)
and https://nxdomain.no/~peter/what_is_bsd_come_to_a_conference_to_find_out.html (https://bsdly.blogspot.com/2025/11/what-is-bsd-come-to-conference-to-find.html)
plus https://nxdomain.no/~peter/yes_the_book_of_pf_4th_ed_is_coming.html (https://bsdly.blogspot.com/2025/07/yes-book-of-pf-4th-edition-is-coming.html)

#pf #packetfilter #bookofpf #networking @nostarch

Upcoming "Network Management with the OpenBSD Packet Filter Toolset" tutorials (covering #freebsd and #openbsd):

2026-03-19 AsiaBSDCob https://www.asiabsdcon.org
2026-06-18 BSDCan https://www.bsdcan.org

See https://nxdomain.no/~peter/pf_tutorial_upcoming_questions_welcome.html (https://bsdly.blogspot.com/2025/05/for-upcoming-pf-tutorials-we-welcome.html)
and https://nxdomain.no/~peter/what_is_bsd_come_to_a_conference_to_find_out.html (https://bsdly.blogspot.com/2025/11/what-is-bsd-come-to-conference-to-find.html)
plus https://nxdomain.no/~peter/yes_the_book_of_pf_4th_ed_is_coming.html (https://bsdly.blogspot.com/2025/07/yes-book-of-pf-4th-edition-is-coming.html)

#pf #packetfilter #bookofpf #networking @nostarch

New blog post: PF Firewall on FreeBSD - A Practical Guide

After years of running PF across multiple FreeBSD servers, I've written up the patterns that work: macros, tables, brute-force protection, NAT for jails, and dual-stack filtering.

Covers everything from basic concepts to production configs, plus a sidebar on authpf for bastion hosts.

If you're running FreeBSD and want a firewall that's elegant, powerful, and actually understandable, PF is worth your time.

https://blog.hofstede.it/pf-firewall-on-freebsd-a-practical-guide/

#FreeBSD #PF #Firewall #Security #Jails #SysAdmin #IPv6

New blog post: PF Firewall on FreeBSD - A Practical Guide

After years of running PF across multiple FreeBSD servers, I've written up the patterns that work: macros, tables, brute-force protection, NAT for jails, and dual-stack filtering.

Covers everything from basic concepts to production configs, plus a sidebar on authpf for bastion hosts.

If you're running FreeBSD and want a firewall that's elegant, powerful, and actually understandable, PF is worth your time.

https://blog.hofstede.it/pf-firewall-on-freebsd-a-practical-guide/

#FreeBSD #PF #Firewall #Security #Jails #SysAdmin #IPv6

Just added short 𝗕𝗼𝗼𝗸 𝗼𝗳 𝗣𝗙 (𝟰𝘁𝗵 𝗘𝗱𝗶𝘁𝗶𝗼𝗻) [Book of PF] review/update to 𝗕𝗼𝗼𝗸𝘀 𝗔𝗯𝗼𝘂𝘁 𝗙𝗿𝗲𝗲𝗕𝗦𝗗 [Books About FreeBSD] article.

https://vermaden.wordpress.com/2022/02/04/books-about-freebsd#book-pf-4th

#verblog #freebsd #openbsd #netbsd #pf #firewall

Just added short 𝗕𝗼𝗼𝗸 𝗼𝗳 𝗣𝗙 (𝟰𝘁𝗵 𝗘𝗱𝗶𝘁𝗶𝗼𝗻) [Book of PF] review/update to 𝗕𝗼𝗼𝗸𝘀 𝗔𝗯𝗼𝘂𝘁 𝗙𝗿𝗲𝗲𝗕𝗦𝗗 [Books About FreeBSD] article.

https://vermaden.wordpress.com/2022/02/04/books-about-freebsd#book-pf-4th

#verblog #freebsd #openbsd #netbsd #pf #firewall

Ouch! Been caught, once again..., by the bug/feature in #OpenBSD #pf parser where a commented line starting with # and ending with \ also comments the next line... #BeenThereDoneThat #SysAdminFail

Ouch! Been caught, once again..., by the bug/feature in #OpenBSD #pf parser where a commented line starting with # and ending with \ also comments the next line... #BeenThereDoneThat #SysAdminFail

acquired - tome of pf

(this is not sponsored content, I just like the book)

thank you @pitrh

https://nostarch.com/book-of-pf-4th-edition

#unix_surrealism #comic #technomage #openbsd #pf #bookofpf