HOWTO Activate NAT on Debian

This article is incomplete and was first written in September 2006
for the BeezNest technical website (http://glasnost.beeznest.org/articles/343).

An example on how to activate NAT on a Debian box (on Etch and up).

First, activate IP forwarding in /etc/sysctl.conf.

Then, you need to activate NAT itself in /etc/network/interfaces:

auto eth0
iface eth0 inet static
        address 192.168.1.254
        netmask 255.255.255.0
        network 192.168.1.255
        up iptables -t nat -A POSTROUTING -o $IFACE -j MASQUERADE

There you are.