DBridges: Flexible Floodless Frame Forwarding

Ethernet has become the de facto layer 2 transmission technology, partly due to ease of use and cost efficiency. The cores of most data centers around the world are based on Ethernet, and large access and core networks are built without IP routing. The inherent simplicity of Ethernet has several drawbacks, including the overhead of network-wide broadcasting and the use of the spanning tree protocol. The academia and the industry have presented numerous solutions to overcome the limitations of Ethernet. Many of these solutions have deployment constraints and often force a change of the whole network.

In this paper, we present DBridges, an efficient solution for building large-scale Ethernets based on the IETF-driven RBridges and SEATTLE. DBridges provide loop-safety, dramatic decrease in broadcast traffic, and resiliency and graceful failover without affecting the plug-and-play vision of Ethernet. The key contributions of our solution are that we are backward compatible with RBridges and can support incremental deployment. We analyze and show these benefits in detail, and present various performance measurements using our proof-of-concept implementation. We estimate that with DBridges it is possible to increase the size of Ethernet broadcast domains at least tenfold.