This document will guide you on how to use a FreeBSD system as a wireless access point. This is intended to supplement the FreeBSD Handbook and not replace it.
Getting FreeBSD to act as a wireless access point involves the following steps:
* Make sure your installation includes hostapd and named (BIND)
* Recompile your kernel for pf support
o pf is not the only way to do this, but I strongly prefer pf to the ipfw/ipfilter and have written the How-To to use it
* Configure NAT (and any firewall rules)
* Install isc-dhcp3-server
* Configure daemons and start them
* One network card to connect to the upstream. This is the external network interface (ext_if). In this How-To it will be fxp0. Yours may differ.
* One wireless card to provide wireless services. I prefer Atheros-based cards, whatever FreeBSD supported card you have is fine, though (wifi_if). In this How-To it will be ath0. Yours may differ.
* Optionally, an additional wired network card (int_if) for wired LAN access (via crossover cable or a network switch/hub). Not necessary, but my system provides both wirless and wired LAN access. In this How-To it will be fxp1. yours may differ.
Downloadable sample configuration files are available at http://tun0.net/ascii/config/freebsd_access_point/.
Read more at Howtoforge.com