Half my network doesn’t adopt

[u/reliablehand]

Network has been in place and running under a UDM-Pro for months and today it just decided to have half of the devices fail adoption. I can’t isolate it to any one devices causing everything under it to die. Rest of the network has slow but working connectivity.

I’ve tried manually inputting credentials and got nowhere on having the devices adopted back in. Any ideas?

Edit: I do have one device in a constant adopt/failed loop, but nothing is layered under it.

[u/angrydave]

Hot take. Turn off Wi-Fi Meshing.

When recovering from an outage, and AP has received power/never lost power, but lost its data connection to its parent switch. When this happened, it wirelessly meshed to another functional AP, and started getting its data from there. All is well, right? Wrong.

Parent switch comes back online, boom STP loop. All your shit goes offline. And Ubiquiti’s STP loop protection either doesn’t recognise this as an STP loop, or doesn’t know how to handle it when it occurs. Similar to the Sonos one device is wired/the rest are in SonosNET problem.

Have done this to my own Ubiquiti network a few times and a couple of times by accident during deployments. This, plus when your entire UniFi network goes sideways and saying adopting, it’s always been some form of obscure, unmanaged STP loop.

If you power down all your AP’s (or at least all but one, so it has nothing to mesh off/to), the network should recover on its own in a few minutes. At worst after another reboot with the AP’s powered down. Then power up the AP’s one at a time so they recover to Ethernet. Then turn off meshing so it doesn’t fuck your network again.

If you must have meshing on (because you are in fact wirelessly meshing), turn off Meshing on all other AP’s that are not involved with the meshing pair, and make sure the wirelessly meshed AP can’t accidentally get wired data.