1. A method of transmitting a communication having a destination node field from a source node to a plurality of destination nodes in a plurality of nodes in a computing system, each node having multiple input ports and multiple output ports, each input port and output port capable of being either enabled or disabled, the method comprising: setting an input port in a destination input port field of the communication; setting bits including at least one don't care bit in a broadcast-area field of the communication; determining from the broadcast-area field of the communication which bits of the destination-node field of the communication are don't-care bits; and transmitting the communication to the input port specified in the destination input port field of the data word to the one or more destination nodes such that (i) the specified input port of the destination node is enabled and (ii) the bits in the destination node address that do not correspond to the don't-care bits in the destination-node field of the communication are identical to the corresponding bits in the destination-node field of the communication, wherein the destination-node field includes low-order bits, and wherein the broadcast-area field of the communication indicates that some number of low-order bits of the destination-node field of the communication are don't-care bits.