Patent ID: 8116310
Filing Date: 2012-02-14
Classification: H04L

Abstract:
1. A method, comprising: operations performed in a network; wherein the network includes an upstream router, a packet switch, a plurality of downstream routers and one or more additional routers; wherein the upstream router is communicatively coupled to the plurality of downstream routers via the packet switch; wherein the packet switch includes a first port, a plurality of second ports and one or more additional ports for communicating with external devices; wherein the packet switch is communicatively coupled to the upstream router via the first port; wherein the packet switch is communicatively coupled to the plurality of downstream routers via said second ports; and wherein the packet switch is communicatively coupled to said additional routers via said additional ports; wherein said operations include: the upstream router, in response to recognizing that multicast traffic is to be sent to each of the plurality of downstream routers, sending a flood prevention request message to the packet switch; wherein the flood prevention request message specifies both a forwarding media access control (MAC) address and a plurality of destination MAC addresses; wherein each of the plurality of destination MAC addresses is a MAC address of one of the plurality of downstream routers; wherein the forwarding MAC address is a MAC address to be subsequently used as the destination MAC address in each of a plurality packets; and wherein each of the plurality of destination MAC addresses identifies one of the plurality of downstream routers to which the packet switch should forward each said packet having the forwarding MAC address as its destination MAC address; and the packet switch, in response to said receipt of the flood prevention request message: determining, based on said plurality of destination MAC addresses, the plurality of second ports is the set of ports that a packet having said forwarding MAC address as its destination MAC address should be forwarded from by the packet switch; and updating one or more forwarding data structures within the packet switch correlating the forwarding MAC address with said determined plurality of second ports based on said plurality of destination MAC addresses for use in forwarding subsequently received packets having the forwarding MAC address as their destination address.