In one implementation, a cluster of network devices forwards packets within the cluster according to a node vector and a cluster database. The cluster database defines a path from each network device in the cluster to every other network device in the cluster. When a packet is received, the receiving network device accesses a forwarding database for egress ports according to a destination address of the packet and accesses the cluster database to identify a first cluster link in the path from the receiving network device to the egress network device. The receiving network device adds a node vector to the packet. The node vector communicates to subsequent network devices how the packet is to be forwarded through the cluster on the path from the receiving network device to the egress network device. The node vector is specific to the network device cluster and operates independent from packet forwarding protocols.