Patent ID: 7920567
Filing Date: 2011-04-05
Classification: H04L

Abstract:
1. A switching hub, comprising: a plurality of ports, each of which has a transmit port and a receive port; a control unit for setting a VLAN-ID for each of the transmit ports and the receive ports of each of the plurality of ports, respectively, the VLAN-ID comprising a subgroup ID of a subgroup constituting a VLAN, and a sub-ID of a group contained in the subgroup ID; a filter processing unit comprising: a receive filter processing unit for referencing the VLAN-ID of the frame, when the VLAN-ID contained in the frame matches a set VLAN-ID of the receive port, permitting forwarding of the frame to a switching processing unit, and when the VLAN-ID contained in the frame does not match the set VLAN-ID of the receive port, discarding the frame, and a transmit filter processing unit for referencing the VLAN-ID of the frame received from the switching processing unit, when the VLAN-ID contained in the frame matches a set VLAN-ID of the transmit port, permitting forwarding of the frame to the transmit port, and when the VLAN-ID contained in the frame does not match the set VLAN-ID of the transmit port, discarding the frame; and the switching processing unit for referencing the subgroup ID of the VLAN-ID in the frame received from the receive filter processing unit and relaying the frame to the port, when flooding the frame, the switching processing unit designating flooding for a destination subgroup indicated by the subgroup ID as a destination of the frame and relaying the frame to the transmit filter processing unit; the VLAN-ID set for the transmit port and the VLAN-ID set for the receive port have the same subgroup ID.