IP multicast over multi-chassis trunk

摘要

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.

主权项

1. A switch, comprising:
a link management module adapted to operate a local interface of the switch in conjunction with a remote switch to form a multi-chassis trunk link, wherein the multi-chassis trunk link is coupled to the switch and the remote switch; a packet processor adapted to identify a join request from an end device coupled to the multi-chassis trunk link for joining a multicast group, wherein the join request is encapsulated in a control message received from the remote switch; a forwarding management module adapted to:
determine whether the switch is a primary forwarder for the multicast group;preclude the local interface from forwarding multicast data associated with the multicast group to the end device in response to the switch not being the primary forwarder; andinstruct the local interface to forward multicast data associated with the multicast group in response to detecting a failure of the remote switch.