PDC traffic crashes switch?

[morganw]

A few months ago we had an Allied Telesyn AT-8000s switch installed by contractors, it would seem to reboot itself every minute or so although a connection would sometimes be present in between reboots.

 

The switch has (allegedly) been sent back to Allied Telesyn and the contractor has told us that we must have a network loop causing the problem. We had the switch brought back today, and after a day of playing with it we have realised that having our Primary Domain Controller on the network causes the reboots, unplug that one server and everything is fine.

 

The final test configuration was the PDC on a fibre link directly into the switch, no other equipment involved, the switch still resets itself.

 

Is it possible that some bizarre server traffic could crash / reboot / reset a switch in under a minute, or is the switch faulty?

 

The contractor is asking me about spanning tree settings on the server, i've never heard of spanning tree settings on anything other than switches.

 

Any advice would be appreciated.

[powdarrmonkey]

Switches should be resillient and drop malformed packets, otherwise that's the simplest way to launch a denial of service attack. Sounds like your contractor is grabbing at straws, I'd replace the switch.

[Oops_my_bad]

Possibly a dodgy network card in the server also?

[FN-GM]

Have you looked into the Event Log in the switch and Server?

[morganw]

We've tried changing the cabling and and swapped to a different network adapter.

The switch is back with the contractor now and we have a temporary unit in place, he has used the serial port in the past to connect to the switch at his office so hopefully he's currently investigating the switch logs.

 

I must confess that I've never done any switch management over any kind of terminal session. Is it relatively straight forward?

[mbhmirc]

spanning tree's only on switch's and it just knocks the traffic off for everything for a period of time it doesn't reboot the whole switch every minute. If it was cat5e i would of said a short but since it's fibre it seems really strange. Did he try swapping the fibre module out?

[morganw]

Yes, it does the same thing with the supplied allied telesyn module and also a borrowed netgear one from another switch.

[mbhmirc]

Yes, it does the same thing with the supplied allied telesyn module and also a borrowed netgear one from another switch.

 

What about plugging the fibre into the other switch? Just to see if it crash's that one too?

[morganw]

No, it's just this switch. PDC is fine going into a netgear one.

I can have everything in the building running on this new switch and it's fine, until I connect the PDC into the mix. All the other switches are behaving as normal.

[mbhmirc]

sounds defo like a switch/firmware fault.