AC1000 router won't connect to LB1121 modem

[misha_n]

I purchased a LB1121 4G/LTE modem and would like to connect it to an AC1000 router and run WiFi through there. SIM card is activated and in the modem, both devices are connected, all lights are green, but when I try to set up the router with the Nighthawk app, it says there is no internet connection. What's going on?

[plemans]

You've basically got 2 routers running. The LB1121 starts up running in router mode with passthrough mode disabled. Which puts you in a double nat and is causing your problem during setup.

https://kb.netgear.com/30186/What-is-Double-NAT

You either need to log into the lb1121 and change it to passthrough mode (disables routing/dhcp function) or you need to put the R6080 in AP (access point) mode which disables its routing/dhcp function.

here's where you can get the manual for the lb1121 that walks you through putting it in passthrough mode. 

https://www.netgear.com/support/product/LB1121

and here's for the R6080 in case you decided on the AP route. 

https://www.netgear.com/support/product/r6080

[misha_n]

Appreciate the help! 

When I first connected the two, though, the modem was in bridge mode with routing and DHCP disabled. I've since reset the modem to factory settings and will try again disbaling the routing functions again, but I don't know if that's the only issue.

[plemans]

Maybe passthrough isn't functioning properly. If it doesn't work, try putting the router in AP mode and seeing if that works.