How to setup Loopback Port Forwarding on OpenWRT Kamikaze

If you use OpenWRT and have a server on your LAN, you probably want to setup loopback forwarding. Here’s how to do it.

These instructions came from this page. I simply want to explain them a bit more, and confirm that these instructions for loopback forwarding work on OpenWRT Kamikaze.

iptables -t nat -A prerouting_rule -d 100.100.100.100 -p tcp –dport 80 -j DNAT –to 192.168.0.2
iptables -A forwarding_rule -p tcp –dport 80 -d 192.168.0.2 -j ACCEPT
iptables -t nat -A postrouting_rule -s 192.168.0.0/24 -p tcp –dport 80 -d 192.168.0.2 -j MASQUERADE

  • Replace 100.100.100.100 with the public IP address given by your ISP.
  • Replace all occurrences of 192.168.0.2 with your server’s LAN IP.
  • Replace 192.168.0.0/24 with CIDR notation for your LAN.
  • Replace 80 with the port you want to loopback forward. 80 is the typical webserver port, 443 is SSL webserver. You probably want to forward both ports, so make a copy of these three lines and change 80 to 443 on the second set.

Put these lines in /etc/firewall.user and restart your firewall by running /etc/init.d/firewall restart at the command line.

You must also have already set up your regular port forwards. You can do this through the Kamikaze web interface.