# Packet Filter

[pf(4)](https://man.openbsd.org/pf), or Packet Filter, is OpenBSD's built-in firewall. Consult the relevant man page, as well as the one for [[pf.conf(5)](/https://man.openbsd.org/pf.conf).
[pf(4)](https://man.openbsd.org/pf), or Packet Filter, is OpenBSD's built-in firewall. Consult the relevant man page, as well as the one for [[pf.conf(5)](/https://man.openbsd.org/pf.conf).

!!Usage

For examples on how Packet Filter is to be used in IRCNow production environments, consult the [sample pf.conf for stable servers](/https://wiki.ircnow.org/index.php?n=Openbsd.PFStable).