A multicast data packet sent from a source node is received by a transit node. The multicast data packet includes a source address and a multicast group address. A hardware cache miss is detected at the transit node for the multicast data packet. The multicast data packet is hardware-flooded onto ports of the network. The flooding consists of forwarding a copy of the multicast data packet to neighbor nodes of the transit node based on virtual local area network (VLAN) membership. A cache-miss copy of the multicast data packet is sent to an out-of-line processing unit where it is processed in software. The processing includes establishing, via a hardware abstraction layer, a hardware cache entry for the multicast data packet. The cache-miss copy is not forwarded onto the network.