Data communication system with distributed multicasting

The present invention relates to multicasting in data communication networking and, more particularly, to multicasting in a local area network (LAN) bridge. A bridge provides distributed multicast forwarding with sub-interface granularity. Forwarding decisions on multicast data packets transmitted on the bridge backplane are made by network interfaces by referencing local multicast databases. Each network interface forwards multicast data packets only on local ports which belong to the multicast group identified in the packet. A management interface transmits forwarding updates to the network interfaces. A particular network interface is made responsible for forwarding multicast packets to management interface for learning.