[HOW-TO] Fix ports not forwarding in DD-WRT
I recently re-flashed my Linksys WRT54G and Motorola WR850G routers with updated DD-WRT firmware after running into some stability issues. So far they have both been stable since the re-flash and have not required manual restarting (I still put them on a scheduled reboot at 3AM). However, when I attempted to run my BitTorrent client, qBitTorrent, after all the appropriate ports were forwarded in the router’s firewall and settings applied in the client itself, no connection could be made. I did some digging around the internet and finally stumbled across this little firewall command for DD-WRT. The problem was fixed after entering the command and rebooting the router.
To apply the command, log into your router’s DD-WRT web interface and navigate to Administration > Commands. Paste the following within the command box and press ‘Save Firewall’. Afterward, you can either ‘Run Command’ or reboot the router to execute.
iptables -t nat -A POSTROUTING -j MASQUERADE
By the way, I’m using DD-WRT v24-sp2 mini build 14929 on the Linksys WRT54G v2 router and build 14896 on the Motorola WR850G v2. The WRT54G operates as the main wireless router; the WR850G is wired to the WRT54G and only operates in AP mode.