openwrt/package/iptables/files/firewall.user

#!/bin/sh
# Copyright (C) 2006 OpenWrt.org

iptables -F input_rule
iptables -F output_rule
iptables -F forwarding_rule
iptables -t nat -F prerouting_rule
iptables -t nat -F postrouting_rule

# The following chains are for traffic directed at the IP of the 
# WAN interface

iptables -F input_wan
iptables -F forwarding_wan
iptables -t nat -F prerouting_wan

### Open port to WAN
## -- This allows port 22 to be answered by (dropbear on) the router
# iptables -t nat -A prerouting_wan -p tcp --dport 22 -j ACCEPT 
# iptables        -A input_wan      -p tcp --dport 22 -j ACCEPT

### Port forwarding
## -- This forwards port 8080 on the WAN to port 80 on 192.168.1.2
# iptables -t nat -A prerouting_wan -p tcp --dport 8080 -j DNAT --to 192.168.1.2:80
# iptables        -A forwarding_wan -p tcp --dport 80 -d 192.168.1.2 -j ACCEPT

### DMZ
## -- Connections to ports not handled above will be forwarded to 192.168.1.2
# iptables -t nat -A prerouting_wan -j DNAT --to 192.168.1.2
# iptables        -A forwarding_wan -d 192.168.1.2 -j ACCEPT