ghost mac addreses locking out 3550 ports

[j.lipsett]

I have enabled port security on all my 3550/4500 ports. Every so often some of them are locked out with 1 of 2 MAC Addresses that do not exsist on my LAN. This happens in a random manner. Has any one else came across this? The two mac addresses are

e8be.5db3.5558 & 5258.5f55.55c5. I have searched the Internet for an associated vendor but no match found?

Is there some explanation for the above as I can honestly say that no other PC has been attached to the ports in question.

[Kevin Dorrell]

I have seen something like this. In my case it was due to a problem with the NIC driver, and was resolved by updating the driver. The PCs that are connected to the ports that fail, are they all the same make/model by any chance?

The other issue that can occur is when a PC is in standby, and the power is removed and re-established - a brown-out. This can cause garbage on the port because the speed/duplex negotiation fails on the port, but the NIC card thinks it is still on standby at the original speed.

Hope this helps

Kevin Dorrell

Luxembourg

[j.lipsett]

Hi Kenin

The PC's are a mixture of Compaq's & Dell's. It has happened to both.They are new so drives should not be a problem, but when the PC is switched off the motherboard/nic still are powered. I'll investigate if they go into a standby status?

May have to configure ports manually for speed/duplex.

Regards

John

[Kevin Dorrell]

I cannot say 100% that is the problem, but it's worth investigating.

Very important: if you hard-code speed and duplex, you must do it on both the PC and the switchport. Having one side auto and the other side forced is a real no-no.

Kevin Dorrell

Luxembourg