I have a GL-MT1300 running latest firmware (4.3.7) and am trying to get it working with a Verizon U620L USB modem. The modem connects and obtains an IP address and default gateway, but will not allow connection to the Internet.
I tried sshing to the MT1300 to check if the modem was in enterprise mode, but when I try to run lssub it says it is not found.
Please help 
If it is a tethered connection the router may need specific drivers to be able to use the modem.
I think the issue is that it’s not being put into Enterprise Mode, which is required. It works on my Mac and when evaluating the mode with lssub, it shows it is in end-user mode. I just can’t figure out how to force it into Enterprise Mode on my GL-MT1300.
It is pulling an IP address and gateway when I look at the Tethering info in the admin GUI. But when testing the Internet access using Multi-Wan, it says no Internet connection is detected.