The bigger picture is that a port on switch A is getting port security triggered by a mac address of a pc connected to a port on switch B. When you do a 'sho mac-address-table interface...' command on the port on switch A, both mac address of the connected pc and the mac address of the pc on switch B sho up in the table. Switch A and switch B are in two separate buildings although the ports are on the same vlan.
