Patent ID: 7911977

Claim:
A method comprising: a first router selecting a designated router for a first multicast group, wherein the selecting the designated router for the first multicast group comprises the first router, in response to the first router receiving an IGMP membership report that comprises an IP address of the first multicast group, generating a first value for the first router and a second value for a second router, wherein the first and second values are generated using a hash algorithm, and using the first and second values to select itself or the second router as the designated router for the first multicast group, wherein the first and second routers are on a network; and the first router selecting a designated router for a second multicast group, wherein the designated router for the first multicast group is distinct from the designated router for the second multicast group, and the selecting the designated router for the second multicast group comprises the first router, in response to the first router receiving an IGMP membership report that comprises an IP address of the second multicast group, generating a third value for the first router and a fourth value for the second router, wherein the third and fourth values are generated using the hash algorithm, and using the third and fourth values to select itself or the second router as the designated router for the second multicast group, wherein the IP address of the first multicast group is distinct from the IP address of the second multicast group.