PFC(1)

📦 version 1.3.20, in alpine 3.22, alpine 3.23, alpine 3.24, arch rolling, debian bookworm, debian trixie, epel 10, epel 9, nixos 26.05, nixpkgs unstable, opensuse-leap 16.0, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 PFC — active precompiled filters generator 💖

okay so bestie, welcome to pfc, the manual page that's about to make your connect-on-demand PPP life SO much cuter. she's the Precompiled Filter Compiler and she's literally iconic. let's get into it 🦋

✨ NAME ✨

pfc — active precompiled filters generator

like. the name says it all. no notes. 💅

🎀 SYNOPSIS 🎀

pfc <expression> >/etc/ppp/your.active.filter

yes bestie, that redirect is doing real work, don't skip it 😭

🌸 DESCRIPTION 🌸

okay so first thing, this manual page is just documenting pfc briefly. a lil appetizer. a vibe check, if you will.

pfc is the Precompiled Filter Compiler — a tool to generate "active precompiled filters". if your pppd supports this feature (and like, not all of them do, so check 👀), you can use this utility to generate the filter files.

the Active Filter allows a connect on demand pppd to figure out what counts as 'interesting' traffic, and then initiate the PPP session. that's the whole point. the tool lets you create the filters, in libpcap format, for use by pppd. common filters are used to ignore traffic (ie: ntp, various protocol keepalives, etc...) so that PPP sessions are not initiated until 'real' traffic actually requires them. it's giving "we don't dial up for nothing" energy. periodt. 🔥

⚠️ important note bestie: the generated compiled filter expression is specific to point-to-point links, and it differs from the format generated by tcpdump -ddd. do not come for me with the wrong format, they are NOT the same, i promise 😭

also, quick reminder — specify precompiled-active-filter=/etc/ppp/your.active.filter in the ppp options file. don't forget or it literally won't do anything 💀

⭐ EXAMPLE ⭐

look at her go:

/usr/bin/pfc ntp and ldap > /etc/ppp/your.active.filter

ate. no crumbs. 🍓

🌈 SEE ALSO 🌈

pfc is from the FLoppy Isdn 4 Linux project — see http://www.fli4l.de/en/home/news/

iykyk 💜

👑 AUTHOR 👑

this manual page was written by Roberto C. Sanchez <roberto@connexer.com>, for the Debian project (but may be used by others). king behavior honestly 🫶

and that's the whole page bestie!! this was the General Commands Manual for PFC(1), dated October 30, 2008 — shoutout to that date, she's an elder but she still slays. mwah 💖✨

📦 where this page comes from