Switches resetting??

[Zourous]

I've not come across this before. We have 4 switches in a cabinet (working as a stack) that have randomly started resetting themselves. When I say reset, I mean they are losing connectivity, and they are losing their stack number for a minute or two before they all come back online. They aren't doing the normal loud firing up of the fans so I don't think its a full restart. The switches are plugged directly into a ups, but the ups seems happy enough and our domain controller server is working off the same ups and isn't going down. The trouble is all our virtual servers are running through these switches to the whole school so everyone just about loses everything and it has happened numerous times now. Anyone have any ideas what is causing this?

[3s-gtech]

How's the heat build-up in there?

[FN-GM]

What sort of switches are they?

[Oaktech]

is the stack redundant stacked or just plain daisy chained? are the stacking sockets built in, or add in cards?

 

Someone I know has had a similar issue which turned out to be a failing add in card in the back of an HP switch taking the whole stack out...

[m25man]

What switches are they?

[Zourous]

I don't think the heat build-up is anymore than it usually is.

 

I think they are 3com 5500 switches which I think are daisy chained. Note sure if they are add-in cards. Will check tomorrow.

 

Interesting if one of them has a dodgy card. I bet that could be tricky to find, when it could be any of the four of them.

[3s-gtech]

Is it possible to remove any of them to test the remainder? Then if it fails, swap and try again?

[Zourous]

Thanks for the ideas. My boss decided to pay out for someone to remote in and have a look around, but they couldn't find anything in particular. When the switch resets, it clears the logs, so now we have the logs writting to the dc in the same cabinet. Hopefully next time we will get the info we need.

[difinity]

Have you looked inside ? Depends on the switch, but could be bad caps.