I decided to wire backhaul all 3 of my WiFi Pro today. Basically doesn't work from what I can see. Initial Mesh topology was working pretty good across 3 floors, 800 - 400 Mbps.
Modem WAN port ----> WiFi Pro WAN port ----> WiFi Pro LAN port ----> 8-port UniFi switch ====> WiFi Pro LAN ports x2
Basically the two switch connected WiFi Pros have no connectivity when backhaul wired to the switch. They work fine when setup as wireless mesh, yet they added fine during setup.
When only one of the two secondary WiFi Pro is connected to the switch it shows as online but no internet connectivity from anything connected to the switch. Switch connected devices I.e. TV works fine when both WiFi Pros not connected to the switch. When 1 or 2 Pros are connected - foobar - constant on/offline.
Have tried Factory reset, tried mesh first then moved to wired, then factory reset started all wired and still no joy.
Changed cables two switches all of which worked fine previously in my UniFi setup.
Gen2 product, this seriously made it out of QA?
I noticed you are using a UniFi Ethernet switch. I believe these are typically smart/managed switches that have "loop detection" (spanning tree protocol) enabled. This interferes with the way Google/Nest WiFi uses that protocol to eliminate the traffic loop that would otherwise occur when connecting secondary units via Ethernet. The solution is usually as simple as disabling loop detection in the switch, though occasionally some switches may also require enabling STP BPDU Flooding when STP itself has been disabled. I typically use unmanaged Ethernet switches that don't have loop detection, and those should work without any configuration changes.
To verify, I would try disconnecting the switch and wiring one of the secondaries directly into the primary's LAN port. Reboot the primary and that secondary. Make sure the other secondary is powered off. Then check the wired secondary's info tab in the Google Home app to verify it shows as "wired" connection type.
Yes, the mesh is still running, hence the loop. So it needs spanning tree protocol to detect the loop and disable traffic through the mesh interface on wired secondaries. The mesh running means it will take over again within a few seconds if the Ethernet connection goes down for some reason.
Ok disabling spanning tree on the UniFi switch didn't help, not sure I can change - via the gui at least - STP BPDU.
However, I have an unmanaged HPE FlexNetwork switch which I have tested and everything appears to work ok. Unfortunately it's a 24 port ToR Data Centre switch so far too big and noisy for the home.
Will have a play with the unifis as I have 6x8ports and 3x5ports from my previous UniFi wireless network which is like to use.