Ip multicast over multi-chassis trunk

Abstract

In embodiments of the present invention, multicast traffic is simultaneously routed via all switches participating in the trunk (can be referred to as partner switches). A respective partner switch synchronizes the local multicast state information with all other partner switches. For a respective multicast group, a plurality of partner switches can be the part of the corresponding multicast distribution tree and obtain multicast traffic from uplink sources. For the multicast group, only one partner switch is elected as the primary forwarder which forwards the multicast traffic via the trunk. Another partner switch can become the primary forwarder for the multicast traffic of another multicast group and provide load sharing of multicast traffic between partner switches. Furthermore, because the partner switches have the multicast traffic and state readily available, in the event of a switch or link failure to the primary forwarder, another partner switch can readily become the primary forwarder.