Patent ID: 6370142
Filing Date: 2002-04-09
Classification: H04L,H04Q

Abstract:
A method of forwarding packets received by a switch, the switch including a plurality of ports, the switch coupled to a plurality of end-stations, one or more of the plurality of end-stations being part of a virtual local area network (VLAN), the method comprising:maintaining a mapping of Internet Protocol (IP) multicast groups to one or more of the plurality of ports; causing at least one member of an IP multicast group on each LAN segment of the VLAN to respond to a group membership query message with a group membership report by suppressing the forwarding of group membership reports onto the VLAN; receiving an IP multicast packet; forwarding the IP multicast packet to each of the one or more end-stations in the VLAN if a destination address associated with the IP multicast packet is an all-systems multicast group; forwarding the IP multicast packet to only those of the plurality of ports that are coupled to IP multicast routers if the IP multicast packet is a group membership report or if the destination address is one that is not known by the switch; and forwarding the IP multicast packet to one or more end-stations of the plurality of end-stations if the destination address is one that is known by the switch to be an IP multicast address subscribed to by the one or more end-stations.