A router node may be configured for communication of multicast traffic in a network fabric which may include a plurality of spine nodes interconnected to a plurality of leaf nodes. The router node may be configured as one of the leaf nodes and serve as a first hop router for multicast traffic. At the router node, a message for flooding the network fabric may be sent based on an indication of communication of multicast traffic for a multicast group from a source device. The message may include at least one spine node identifier of at least one preferred spine node joined to the multicast group at the router node. The message may be for indicating, to at least one of the leaf nodes, to prioritize joining to the multicast group at the at least one preferred spine node according to at least one spine node identifier.