All Ports lit up on all 3Com 3300 Switches? Why?

[ITTime]

I have about 10 3Com SuperStack II 3300 Switches that randomly light all ports solid. This will resolve itself in a couple minutes but the network crawls in the meantime. I have been running the 3Com Network Supervisor to try and diagnose but I get different reports each time....missing a connection point for between 5 & 40 computers! This varies with no pattern I can see. These are not stacked and each switch is connected on port 1 to a Cisco Catalyst. I have upgraded the firmware to the latest on each and the settings are the same also.

Any suggestions or directions to look?

Thanks for any ideas as this is driving me nuts!

 

[NetAdmin2004]

To me it sounds like you have something creating a broadcast problem on your network. I would run a network sniffer program and capture the data when and while this is happening if you can. I have used those exact 3Com Switches before and noticed that mine did that also. I ran a sniffer package and found that someone (another employee) was running an auditing tool to scan for all of our PCs. While he ran the program, it sent out broadcasts like crazy causing horrible network performance. We also had a problem with broadcasts because engineers were putting PLCs on the network, which they are notorius for broadcasting issues unless you n=know how to stop it.