smart poe switch closing down ports

[nicke20]

I recently bought the above switch to make my home network a bit neater, has a router going in and a ubiquiti cloud key plugged in running 4 wireless ap's it then has a bout 10 devices plugged directly in and 3 ports going off to un managed switches with the ussual stuff hanging off those, wirelass ap's computers, cameras etc. My old system was two unmanaged 8 port gigabit switches daisy chained together and poe injectors where needed. Now im having problems, i can plug almost everything in but when i come to the last two ethernet cables both going to switches with multiple devices attachedI plug one in ok, but as i plug the second in the first one all the lights on the port go off at both ends??

all cables are ok, I have checked all ip addresses (37 of them) and none conflict that i can find. I have switched off all the meshing on the wireless ap's (each switch had a wireles ap on it.

Ideas please for a none network gurus

is there a feedback loop?, how do i find / stop it?

many thanks, nick

Oh i updated the firmware to the latest (took 4 or 5 seperate updates to do)

[schumaku · Accepted solution]

Tha'ts the classic Sonos STP/l2 loop issue - if all Sonos players are wired, disable WiFi...

FWIW: The L2 loop existed before on your unmanaged switches - but you have never realized there is a problem and the network failed to perform well.

[nicke20]

Bit more info

going into the gui, it is reorting a level2 loop

now port 8 on the config page is showing as diasbled and port 17 as enabled

If i re enable port 8 admin mode then port 17 drops out and vice versa

the topology hasnt changed from my pre non managed switch days 

can the loop be wirelessly?

could it be from the sonos system?

AFAIK i have no physical wired loop

[nicke20]

Im hoping i have cured my L2 loop myself

sonos play 1 wired and picking up wifi, one from one branch of main switch one from another

ill look at it all againn tommorow

[schumaku · Accepted solution]

Tha'ts the classic Sonos STP/l2 loop issue - if all Sonos players are wired, disable WiFi...

FWIW: The L2 loop existed before on your unmanaged switches - but you have never realized there is a problem and the network failed to perform well.

[nicke20]

every day is a school day

thank you for confirming and giving a propper explanation to what i had found by the good old method of plug one thing in at a time till it falls over!

Thank you