Normally it cannot, at least not for the same VLAN. Normally it will be in the CAM table for the access port, and in the neighboring switch on the downlink port that leads to the access switch.

It is hard to imagine a scenario where the same MAC address is on an access port in one VLAN, and on the uplink on a different VLAN, but I can think of one counter-example. Older implementations of Solaris used the same MAC address on all ports of a multi-port NIC. If you had different Sun ports connected to different switches in different VLANs, then you would see the phenomenon that you are describing.

Perhaps you could post the evidence, because I am sure that there is to this question than you are telling us.

Kevin Dorrell

Luxembourg