Unifi access points disconnected

[beany1]

Hi all,

 

So got a crazy annoying one here.

 

Around the site we have 20 Unifi AP, all running latest firmware and latest unifi controller.

 

All of sudden yesterday morning all 20 AP went down - displayed as disconnected in the controller. They are connected to four different switches (HP V1910) at different locations within the school using the supplied POE adapters. Yesterday I unplugged all POE adapters from the power from only 1 cabinet for 6 of the AP, and the 2 switches, once this was restarted the access points came back on - all of them! including the ones connected to different switches in different cabinet.

 

Looked on switches no error messages or any indication of port / storm or any other control / restriction. So I was at a loss, then 8 oclock last night they all went down again. Unfortunately restarting the same cabinet did nothing, but restarting the other cabinet they all did show back up in the controller...for a brief moment and disappear, but they won't stay on.

 

All DNS seems to be working fine, wired network is working as usual. Unifi a name record is there and working.

 

Using the Unifi Discover utility shows them when they have first started but they once again go to "disconnected" Tried a new access point with new POE adapter - same as above works for a while then disconnects.

 

Completely at a loss what to try next! Any help anyone can give would be greatly appreciated!

[TronXP]

Have you restarted the controller software?

[beany1]

oh yes, restarted software, server etc!

[beany1]

OK, what could cause a switch to stop access points from working?

 

The moment I restart any of the switches all the access points come up until the switch has finished booting up...then the access points all slowly disconnect once again? This includes access points that are nowhere near directly connected!

[TronXP]

Do you use vlans or have changed anything on the switches?

[beany1]

Nope and nope! the last time there was any alterations was 176 days ago!

[localzuk]

My thought is that there could be something else using the same IP address as the controller server? So, the devices are getting confused as to what to talk to.

 

Have you tried unplugging that server and pinging its address afterwards from another machine, to see if there's any response?

[beany1]

Tried that too thanks! No response to the server controller IP when its disconnected, checked in DHCP / DNS for anything erroneous. Nslookup for server name or 'unifi' returns the correct address for the controller.

 

I believe I have narrowed it down to a single switch! When it is turned off or rebooted all the access points come back on...this switch is right at the edge in a separate building connected by fibre! Before when I was rebooting particular switches I believe its because it was no longer in contact with that switch...

 

I've upgraded the firmware on said switch and now the points are staying back up! Now I'm scared that this is temporary and the problem will come back!