Extreme Networks, Inc.

Vanitha Neelamegam

Donald Bruce Grosser, Jr

Balasubramanian Ramu

Maruthamuthu Palani

Kannan Selvaraj

A switching device supports a mixed mode of operation using both layer 2 and layer 3 multicast forwarding tables for multicast forwarding of packets. In the mixed mode of operation the switching device programs multicast forwarding entries in a corresponding layer 2 or layer 3 table depending on a type of protocol to be used for multicast forwarding. The switching device programs multicast forwarding entries in the layer 3 table for multicast packets forwarded using layer 3 routing protocols, and in the layer 2 table for multicast packets forwarded using layer 2 protocols. The switching device converts layer 3 multicast information to layer 2 multicast information before programming multicast forwarding entries in the corresponding layer 2 table.

Apparatus and method for multicast data packet forwarding

A switching device receives a data packet and searches for a layer 3 multicast destination address specified in a header of the received data packet in a layer 3 multicast forwarding database table. The switch searches for a corresponding port list in a layer 3 egress table if the layer 3 multicast destination address is found. However, if the layer 3 multicast destination address is not found, the switch searches for a layer 2 destination address specified in header of the received data packet in a layer 2 multicast forwarding database table, and the switch searches for a port list in a layer 2 egress table if the layer 2 destination address is found. If neither the layer 3 or layer 2 destination address is found in the searches, the switch discards or floods the received data packet out all ports of the switching device.

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Chennai, India

Vanitha Neelamegam