I have a raspberry pi connected via ethernet to the router and I have setup port forwarding to work with it on port 80, hitting the apache http server - this works fine.
The problem occurs when I plug in my mobile sim dongle to use as a SMS gateway. I can connect to my raspberry pi locally still on http://192.168.0.11/ for example - so I know it is still connected to the network, but the port forwarding stops working. I know the dongle also has an internal IP address on 192.168.1.1 as opposed to the local ip for the ethernet connection (192.168.0.1).
How could I get port forwarding to work?