2960X switch keeps removing itself from the stack

[sonicimage1]

Dear experts,

One of the C2960X switches, which is member 5, keeps removing itself from the stack (FlexStack - there are 5 members in it). I tried to research on the issue on the Internet but couldn't find anything useful. Decided to write it here. If anyone can provide any reasons why it may be happening, and how to troubleshoot and resolve. All 5 switches are PoE 48 ports. There is no IOS incompatibility. I will be very grateful for any help. Thanks.

Regards,

Lucia

[Mark Malone]

Hi

what alert are you receiving in logs

have you tried moving stack cables around swap them incase its a physical problem with 1 of the stack cables to rule it out to see if the issue follows the cable

what IOS version are your running on the stack

[sonicimage1]

I don't think we have syslog server. The IOS version is 15.2(2)E. We can't swap the cables whenever we want as it's a production environment and lots of hosts (PCs and phones) are connected to the switches. We restarted the offending switch, it came back fine for now. But I thought there might be a reason why one keeps removing itself.

[Mark Malone]

I have seen switches fall out of stacks from faulty stack cables that's why I suggested moving them around or swap it completely if you have a spare one if its constantly sw5

Another cause is that particular switch may have triggered something in its software a bug that may be just effecting that connection

The log alert is important as well to see what comes before and after the fact it could identify something as the trigger

[paul driver]

Hello

I would definitely investigate the physical aspect and start with the cabling and as suggested by mark

I had a faulty stack member doing exactly the same - It turned out to be fluff / dust lodged inside the  flex stack cabling pin - I didn't know this as I just swap out the cable 

I am blind as a bat and it was my colleague who noticed it!

res

Paul