1 Introduction

The OpenBSD Packet Filter (OpenBSD PF) is the stateful firewall package that is part of the OpenBSD kernel since OpenBSD 3.0. This document describes how to set up and manage PF rulesets and NAT mappings.

1.1 Intended audience

The intended audience for this document are system- and network administrators with at least a basic knowledge of (inter)networking and the network protocols involved. Knowledge of other firewall systems is not required, but can help in mastering the more complex topics.

1.2 Status

This document is currently a work-in-progress, so not everything regarding OpenBSD PF may be covered yet.

Todo list:

• Network Address Translation
• IPv6
• more notes regarding the extensive feature set of the pfctl command
• AuthPF

1.3 Copyright and license

The OpenBSD Packet Filter HOWTO version 20020405.2
Copyright (C) Wouter Coene, 2001, 2002.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
• The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission.
• This software may not be mass-distributed for sale without informing the author at least two weeks in advance.

THIS DOCUMENT IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

1.4 Contacting the author

You can contact the Wouter Coene through email at wouter@inebriated.demon.nl, or via snail-mail:

   De Deel 17
   3471 EN Kamerik
   The Netherlands