bad ports on Catalyst 2960G?

Unanswered Question

My employer is expanding we are installing some new servers and a new 2960G 48 port switch. After spending countless hours of trying to figure out why 2 of the 3 servers were not talking correctly, I started looking more at the switch. Seems there are four ports that are not working correctly. Ports 9, 10, 11 and 12. The equipment plugged in there can get a DHCP lease, but anything as far as file transfer etc (in Windows Server 2003) fails.

I've switched cables, and NICS, no luck. Moving the gear to ports other than 9-12 and everything works fine.

Plugged a laptop in to port 9 and started pinging a server. Small packet sizes are no trouble. But larger packets seems to drop at about 35%.

using win XP, i ping a file server with a 3 byte packet for a couple hours with 100% success.

300 byte packet gets 35% drop rate.

Has anyone ever seen something like this before?

How could I troubleshoot the issue? Nothing is being logged on the switch. The POST process has no errors (laptop plugged into the console port to see messages) I wiped out the config and started over with the nearly blank cisco defaults, same thing.

It's a new switch, so the vendor is gonna swap it. But I'd like to know what I could have done to save myself all the hours I've been messing with this. I barely know my way around the CLI, is there some kind of test I can trigger that would find an issue like this?

I have this problem too.
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glen.grant Tue, 02/12/2008 - 12:59

Check the ports and see how the speed and duplex are set for the switchports , they must match how the server and client pc nic cards are set. If the switchport is auto for speed and duplex then the nic cards must also be set as auto and not hardcode to a specific speed and duplex. If its not a speed/duplex mismatch then it could be hardware though usually it will be the port either works or it doesn't and not partially working.


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