IP multicast forwarding in MAC bridges

The invention provides novel methods of forwarding multicast data packets to selected egress ports in a MAC bridging environment. A multicast data packet is received via an ingress port. A source IP address and a destination multicast IP address are retrieved from the multicast packet. In a forwarding database, different groups of egress ports correspond to different combinations of a source address, a destination multicast address, and a virtual local area network identifier (VLAN-ID). The forwarding database is accessed, based on the retrieved source address, the retrieved destination multicast address, and a VLAN-ID, to thereby determine a corresponding group of egress ports. The multicast packet is then forwarded to the corresponding group of egress ports.