光学知事隅

Administration -> Remote Access section:
This section is for configuring how to access the router from the WAN (Internet), not the LAN. If you are trying to change the port to access the router’s UI from the LAN side, then you need to do the following in a telnet/ssh window:

Change 3128 in the code above to the port that you want to access the router’s UI from the LAN side.