Can't find source of fragmented or bad data

[egnilk66]

We have 5 3COM switches, two 3COM Hubs, and an HP ProCurve switch and in the past week we have had about 12 total meltdowns... By Meltdown I mean that all of the connections drop and four of the 3com switches go into to seizures. all the lights are blinking in usion at about a billion blinks a minute. The firewall still has connection to the outside those connections seem to be VERY limited.....limited or none at all. What is the program that you would recommend to sniff out the bad packets? Or, what steps would you take to troubleshoot this?

DJK

 

[rwullems]

a good free sniffer to start with would be packetzyer (networkchemistry.com) or ethereal. As you have two hubs, I eould start to plug in a sniffer there to see what traffic is passing during one of these unhappy events.
regards,
robert

Robert Wullems
Network Specialist
SCP/SCE/SCM/CNX/MCP/MCSA/Network+/CNA
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If you can Sniff it, you can solve it!
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[netmanrick]

I would check the port settings on the hubs and switches.
Ensure nothing has changed/reconfigured.
It sounds almost as if STP is starting when you have a "Meltdown". I would disable unused/inactive ports.
Any chance the pc/server folks are doing upgrades/maintenance?
I would verify the core links first,then branch out.
Sniffer,tracert,ping should help you.Do you have a NMS product ?

Rick Harris
SC Dept of Motor Vehicles
Network Operations