I was trying to get this to work at someone else’s house, and it didn’t. When I got back into town, I tried it at my house and hooked it up the exact same way, and it worked. The only thing I can think of is their ISP was MAC address filtering, not letting another router on the network. (Rise Broadband has been known to do that.) In any case, it works as-is at my house. I’m going to update the firmware here and try it at their house next time I go there.
The only hole in my theory is I did try to clone a MAC address of a device on the network, but, while I was doing it, I had that same device hooked up to the LAN side as well… so that may have messed with the layer 2 stuff. Not sure.
I’ll reply if I ever get this going, but it will be a long time before I am able to travel back to their house.