Data centers are growing in importance since computation is moving from personal computers to the Internet. Data centers often use Ethernet as the network fabric; however Ethernet presents fundamental limitations to scalability. This work examines the design, implementation, and characterization of the Axon, a network device that overcomes Ethernet's scalability limitations while maintaining the simplicity of such devices. Axons use cut-through routing to reduce the latency of communication and source-routing both to eliminate the spanning tree and to reduce state within the network. Using just one redundant link in small network has been shown to give a 96% increase to UDP bandwidth and a 63% increase to TCP bandwidth. Experiments confirm that an Axon's latency is an order of magnitude faster than that of a store-and-forward switch in an uncongested network, thereby increasing the potential diameter and improving the scalability of an Ethernet network.