I have a wr31 modem installed remotely, and with it are 2 devices connected to the ethernet ports. I want to open the webpage of one of the devices. I can connect to the modem via a VPN, at 10.5.99.XXX but the devices on the modem’s network are 192.168.0.XXX.
Enable NAT on your mobile interface for both IP address and port.
Setup IP Port Forwarding to the device.
ex. External Min port 81, External Max port 81, the IP of your device “Forward to Internal IP Address” 192.168.0.xxx, Forward to Internal port 80
Now once that is setup you would connect from the outside to the modems IP plus :81 (port)
ex. 166.123.321.123:81