Patent ID: 7899928

Claim:
A method for operating a node in a layer 2 network to handle multicast traffic, said method comprising: receiving at a switch within said layer 2 network, via a first port, an Internet Group Management Protocol (IGMP) join message for a multicast distribution group, said IGMP join message received from a neighbor switch in said layer 2 network; establishing multicast state information at the switch for said multicast distribution group based on said join message, if such state information has not already been established; adding said first port to a port list associated with said state information at the switch, said port list being used to select ports for forwarding received multicast traffic of said multicast distribution group; forwarding said IGMP join message from the switch towards an attraction point of said layer 2 network via a spanning tree defined within said layer 2 network, wherein the attraction point is a root bridge and layer 2 switch in said layer 2 network, and said IGMP join messages are forwarded from the switch towards the attraction point without the use of layer 3 routers; receiving at the switch, multicast traffic addressed to said multicast distribution group and transmitted from the attraction point; and forwarding said multicast traffic via a multicast distribution tree formed based on said spanning tree, wherein forwarding said multicast traffic comprises forwarding said multicast traffic towards the root bridge via a port selected according to said spanning tree, the root bridge located at a root of said spanning tree.