Patent ID: 7756147

Claim:
A Virtual Local Area Network (VLAN) based data packet transmission method, comprising: receiving a data packet from an input port of an Ethernet bridge device; determining a VLAN ID in the data packet; searching a VLAN ID table for a record matching the VLAN ID, wherein the VLAN ID table stores correspondences between VLANs and member ports, and each of the VLANs comprises at most two member ports; if the record matching the VLAN ID includes no member port, or if the record matching the VLAN ID includes two member ports and neither of the two member ports is the input port, modifying, by the Ethernet bridge device, the record matching the VLAN ID in the VLAN ID table to include only the input port as a member port; if the record matching the VLAN ID includes one member port and the one member port is not the input port, modifying, by the Ethernet bridge device, the record matching the VLAN ID in the VLAN ID table to include first and second member ports, the first member port being the input port; if the record matching the VLAN ID includes the input port, not modifying the VLAN ID table; and forwarding the data packet by the Ethernet bridge device according to the stored correspondences between the VLANs and the member ports in the VLAN table.