Cisco 2950 Disconnect

[Guest_imported]

Hi there !

Strange problem with a Cisco 2950-24T. The switch is brand new, with its default parameters. Nothing has been changed except its IP address.

What i got is this: Client computers (recent Dell p3 computers with built in 3com NIC: 3c920 - a variant of the 3c905c) get disconnected from the network and reconnected some seconds later. Nic are set to auto-neg.
Another problem we get with the same config is the client computers, running w2k complaining in the eventlog their IP address is already in use ! (they are all using DHCP !)

And now for the more weird thing: if i replace the cisco switch with a basic 3com superstack III switch, all my problems dissapear !

I've also tried with another cisco: a 3548XL and... EXACTLY the same problem as with the 2950 !
Never saw this before.

What i've already tried is to activate PortFast, replace the server NIC, connect only 2 computers on the network, the server and one W/S. I've completely re-installed the server and W/S recently for another reason and still got the same problems, so i'm sure its linked to the Cisco !
(and remeber it works perfectly well with a basic 3com)

Thanks for your Help

 

[Guest_imported]

Don't leave autonegotiation on at either end.
Tell the switch to use full duplex and whichever speed you want.
Do the same to the PC.
Your problem will disappear.

 

[dihu]

We have had the same problems long time ago ,
it is not a problem but you can solv it if you want you must disable in the pc the powersave mode than this masage with not longer apaer.