Quote Originally Posted by ctaranto View Post
Thanks for that suggestion.

I think I need my head examined. Maybe it's because I woke up early this morning and not thinking straight.

I changed my setup (again).

Cable modem -> WRT -> RT

WRT is 172.20.0.1
RT is 192.168.15.1

Connected WRT LAN to RT WAN

On the Internet Setup page, should I have "Obtain IP automatically"? If so, should it get a 172.20.0.x address?
Each router has a LAN side and a WAN side. The RT's 192.168.15.1 is the address on the LAN side. Yes, you need to "Obtain IP automatically" for the RT and setup the WRT to do DHCP. The RT's WAN address will be in the same subnet as the WRT's LAN side. In future posts specify whether you're listing a WAN or a LAN address for the device, which will be helpful to us readers. And, yes, your Cable modem -> WRT -> RT config is correct.