Apparatus and method for multicast data packet forwarding

摘要

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.

主权项

1. In a switching device, a method comprising:
receiving a data packet; searching for a layer 3 multicast destination address specified in a header of the received data packet in a layer 3 multicast forwarding database table; searching for a corresponding port list in a layer 3 egress table if the layer 3 multicast destination address is found; if the layer 3 multicast destination address is not found, searching for a layer 2 destination address specified in a header of the received data packet in a layer 2 multicast forwarding database table; and searching for a port list in a layer 2 egress table if the layer 2 multicast destination address is found; and performing an action on the received data packet if the layer 3 multicast destination address is not found and the layer 2 multicast destination address is not found, the action being one of: discarding the packet, flooding the packet out all ports of the switching device excluding the port on which the packet was received, or sending the packet to a processor for further processing or learning.