So if you’re like me, and bought a WZR-HP-G300NH2 and was disappointed to find the lack of NAT loopback capabilities, your solution is below. Just go into the “Administration” menu and the “Commands” submenu. Save the text string below as a “Firewall command.” In other words, paste the command in, and then click the “Save Firewall” button. It will now apply itself after every reboot. Be sure to paste it as a single line.
Be sure to change the network (“192.168.1.0″) to the appropriate address of your network.
iptables -t nat -I POSTROUTING -o br0 -s 192.168.1.0/24 -d 192.168.1.0/24 -j MASQUERADE