R7450 No Internet when Connected to Modem

[laclaus]

I have a Netgear LM1200 modem with a T-Mobile sim card.  When I connect the modem directly to my laptop with the ethernet cord, I have internet connection.  When I connect the ethernet cord to the R7450 router, there is no internet.  I have the modem set to bridge.  I have followed all the steps in the Netgear app to power off the modem and router and restart the devices, but I still do not have internet connection. In the app, the message I receive is that the wires are connected correctly but no internet is detected. How do I solve this?

[plemans]

By default the LM1200 should function in bridge/passthrough modem. So you shouldn't have needed to go in and set it. You might start back at stock and reset the LM1200 just in case something else you changed is causing the issue. I'd just write down your apn info in case you need it. 

You also need to make sure that you don't connect anything else to the lm1200. After you've reset it, connect the router to the LAN port on the LM1200 to the WAN port on the R7450. Don't use the WAN port on the LM1200.