An InfiniBand switch fabric is described. This InfiniBand switch fabric includes a hierarchy of switches having physical ports. These physical ports have associated local routing tables for nearest-neighbor connections to the physical ports. Moreover, relationships between the nearest-neighbor connections to each of the physical ports specified in the local routing tables are based in part on network-layer global identifiers that are assigned based on the hierarchy. Furthermore, local routing tables in the switches facilitate paths or routes for packets through the InfiniBand switch fabric without using a global routing table in the switches. In addition, the InfiniBand switch fabric includes a fabric manager, coupled to the switches, having the global routing table to assign the network-layer global identifiers.