Patent ID: 8310917

Claim:
A switching hub for processing a VLAN frame transmitted through a transmission line of a ring network, comprising: two ring ports connected to the transmission line of the ring network; a forwarding processing mechanism for, when one of the two ring ports receives the frame and when a VLAN in which the received frame belongs is a VLAN only through both the ring ports, forwarding the frame to the other ring port without performing FDB learning on the frame, wherein the forwarding processing mechanism includes a VLAN determination unit for determining whether or not the VLAN in which the frame belongs is a VLAN only through both the ring ports, and a transmit processing unit for, when the VLAN in which the frame belongs is a VLAN only through both the ring ports, forwarding the frame to the other ring port, wherein the forwarding processing mechanism includes an address learning unit for, when the VLAN in which the frame belongs is not a VLAN only through both the ring ports, performing FDB learning on the frame; a destination port determination unit for, when the VLAN in which the frame belongs is not a VLAN only through both the ring ports, retrieving from an FDB and determining a destination port of the frame; and a transmit processing unit for forwarding the frame to the destination port determined by the destination port determination unit.