Source-initiated distribution of spine node identifiers of preferred spine nodes for use in multicast path selection

A router node comprising:

• one or more processors;
• a plurality of interfaces configured to connect in a network fabric comprising a plurality of spine nodes interconnected to a plurality of leaf nodes, wherein the router node is configured as one of the leaf nodes;
• the one or more processors being configured to:
• send, via an interface, a message for flooding the network fabric to communicate the message to other leaf nodes in the network fabric based on an indication of communication of multicast traffic for a multicast group from a source device, the message including at least one spine node identifier of at least one excluded spine node to exclude from joining to the multicast group for the communication of the multicast traffic;
• and
• forward the multicast traffic for the multicast group to one of the plurality of spine nodes other than the at least one excluded spine node indicated by the at least one spine node identifier.

A method comprising:

• at a router node configured for communication of multicast traffic in a network fabric comprising a plurality of spine nodes interconnected to a plurality of leaf nodes, and further configured as one of the leaf nodes,
• receiving a message which is flooded in the network fabric by an originating leaf node which is operative to forward multicast traffic for a multicast group from a source device, the message including at least one spine node identifier of at least one excluded spine node;
• receiving, from a receiver device, a request to join to the multicast group for the communication of the multicast traffic;
• and
• joining to the multicast group at one of the plurality of spine nodes other than the at least one excluded spine node indicated by the at least one spine node identifier for the communication of the multicast traffic to the receiver device.