Hi, count me among the many who have had trouble getting AT&T's BGW-320 to play nicely with Nest mesh. I've tried both of the following configurations. Both have resulted in eventual failure of the mesh network (meaning the network is discoverable, but not connected). Sometimes it takes two days, sometimes it takes several months--but I inevitably get the dreaded "[Network Name] has lost connection to the internet" notification on my phone.
This has been going on for over a year, and that whole time, the AT&T connection has been rock solid. When the Nest is working, it shows a great connection (mesh test and speed test). So it's feast or famine.
1. All the things you're supposed to do: Put the gateway in passthrough, turn off AT&T packet filtering and firewall options (and wi-fi radios), set a static MAC address to the Nest primary router. This of course results in the Nest mesh being the only wi-fi network in the house, so failure becomes very disruptive.
2. Do what you're not supposed to: Leave the AT&T gateway alone (even the radios), and simply connect the Nest primary router to it. The keeps the AT&T wi-fi available when the Nest inevitably fails (so, less disruptive).
My 2,700-sqft home setup is:
Origination
AT&T BGW-320 next to a brick fireplace in my first-story office --> Cat6 to Nest --> Unmanaged Switch --> Cat6 to ethernet ports that run through the house. (The gateway has to be there, and its only outbound Cat6 cable is to Nest.)
Mesh Points
1. First-story, one room away (b/c brick fireplace), connected wirelessly
2. Second-story, connected to ethernet port
Also Worth Noting?
In addition to #2 above, the switch services ethernet ports to my TV room (TV is hardwired) and another unused port upstairs.
I can usually "fix" the issue by unplugging cables and power from the primary router (and gateway, if necessary), and then re-plugging. But recently, the failure was so bad that I had to factory reset the Nest mesh.
Does anyone have additional advice or ideas? My next move is to abandon the mesh, and try using one backhauled Nest router in bridge mode to extend the AT&T wi-fi via ethernet. If that doesn't blanket the house, and since Nest doesn't support bridge with multiple routers, then I'll have try an Airport Extreme or similar. My concern is that I may end up with multiple networks / duplicates of the same one.
