Switch overloading causes net problem

[stergiosnik]

Hello all.

From time to time in random periods I face the following problem.

Suddently all network devices in LAN (servers, routers)stop responding. I ping them and I get something like this:

Reply from 192.168.x.x bytes=32 time=230 TTL=64
Reply from 192.168.x.x bytes=32 time=30 TTL=64
Reply from 192.168.x.x bytes=32 time=120 TTL=64
Reply from 192.168.x.x bytes=32 time=50 TTL=64
Request Time out
Request Time out
Reply from 192.168.x.x bytes=32 time=12 TTL=64
Reply from 192.168.x.x bytes=32 time=59 TTL=64
Request Time out
Request Time out

This symptom appears to all devices that are installed in the LAN.

In order to resolve this problem I begun switching off the switches one by one in order to isolate the problem. I finally determined the switch that if I switch off then the problem is resolved.

I replaced this switch 15 days ago but now the problem occured again. I switched it off again and the problem was resolved so I concluded that it is not a switch problem. The switch becomes overloaded for some reason.

This problem occures randomly 2-3 times per month.

Do you know what might be the cause of the problem?

Thank you in advance.

Stergios

 

[Noway2]

Is it possible that a device connected to the switch starts jabbering and by turning off the switch you are disconnecting that device from the network? Perhaps you could try disconnecting each device from the switch one at a time?

 

[VinceWhirlwind]

On the switch where you have found the problem, look at the port stats when the problem occurs - you should be seeing one or more ports with a very high input rate. That would be your culprit.
Ideally, use a remote monitoring tool (using SNMP) for this.

 

[SimonDavies]

Whats the switch? Is it intelligent or a dumb switch?
Are you using any network diag tools?

Get a hold of wireshark and run it and see what it reports back.

Simon

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