Patent ID: 8018964

Claim:
A network router implemented method comprising: associating a first multicast state entry in a multicast routing table on the network router with a first class, wherein the first multicast state entry identifies a first multicast state of a first multicast group, and the first class identifies a first priority; associating a second multicast state entry in the multicast routing table with a second class, wherein the second multicast state entry identifies a second multicast state of a second multicast group, and the second class identifies a second priority; and selecting one of the first and second multicast state entries, wherein said selecting is performed in response to a determination that an upstream router that is part of a first multicast distribution tree for the first multicast group and part of a second multicast distribution tree for the second multicast group is unavailable, said selecting is determined according to highest priority provided by the first and second classes, and said selecting is performed by a processor in the network router.