This attribute is the port name through which the address was learnt.
This implies that the frames that are destined for a station whose MAC
address is the same as the address, will be forwarded through the bridge
port indicated by the attribute port.
The attribute port is a string of the form 'BridgePortName-i', where
BridgePortName is the abbreviation of the corresponding bridge port
and i is the instance identifier of the ProtocolPort, the bridge port is
provisioned under. For example a TransparentBridgePort provisioned
under ProtocolPort/myport would have a name TBP-myport.