I have AR300M with 2.263 firmware on it. When I click on “Advanced settings”, I get a popup like the attached picture. On clicking OK, same user interface is shown. I don’t see advanced user interface.
If I use the URL using router’s IP address, it is working fine. In my case, I connect to web interface using its wan ip address http://10.88.77.66:8080/cgi-bin/luci, it doesn’t work.
It looks like a bug to me. The Luci interface doesn’t understand if the address has a port number embedded in it like I have (i.e. :8080).
Other option is to make the web server bind to port 80 on wan as well as lan interfaces. I don’t know how to do that.