Minimizing ARP Broadcasting in TRILL

Ethernet was originally designed to be a cheap and easy to use communication medium between networked computers. Recently, growing interest in using Ethernet technology in access and carrier backbone networks has increased the motivation to solve the scaling issues of the original Ethernet. There has been extensive research and proposals for extending Ethernet networks to scale better in relation to the amount of end-stations in the network. One of the proposals is the routing bridges (RBridges) design, and the routing protocol they use, TRILL. RBridges are a step forward for Ethernet switching technology, offering better scaling characteristics than conventional STP bridges. Yet, RBridges do not take into account the growing interest in mobile Ethernet devices, and supporting mobility events directly on top of the link layer. Additionally, RBridges still rely on flooding Ethernet frames across the network when the frames are destined to unknown end-stations or sent using a broadcast Ethernet address. In this paper, we present an implementation of the RBridges base specification on the Click modular router. Additionally, we present a solution and a proof-of-concept implementation on how to eliminate one of the largest sources of broadcast traffic in an Ethernet network, the address resolution protocol (ARP) requests. Our solution proposes building a distributed hash table based ARP information store, across the whole Ethernet network.