Patent ID: 7460542

Claim:
A virtual local area network (VLAN) tagging method in a data communications switching device, the method comprising the steps of: receiving a protocol data unit (PDU) on a port with the port operable in at least 1 of at least 3 VLAN tagging modes; determining the VLAN tagging mode associated with the port; and if the determination is made that the port is operating in a first of the at least 3 VLAN tagging modes, then determining a default VLAN identifier associated with the port; if the determination is made that the port is operating in a second of the at least 3 VLAN tagging modes, then: determining if the received PDU comprises an incoming VLAN tag, if the incoming VLAN tag is present, then determining the VLAN identifier of the VLAN tag, and if the VLAN tag is not present, then determining the default VLAN identifier associated with the port; and if the determination is made that the port is operating in a third of the at least 3 VLAN tagging modes, then determining a protocol-dependent VLAN identifier associated with the protocol type of the received PDU.