Hidra: Hierarchical Inter-domain Routing Architecture

The size of the Internet’s forwarding table is growing rapidly, generating concerns about the ability for high performance routing equipment to economically keep pace. The primary contributors to this growth are end site multihoming, traffic engineering, and in the foreseeable future, IPv6 deployment. This paper presents HIDRA, a hierarchal network architecture designed to reduce both the immediate size of the Internet’s forwarding table as well as its growth rate while maximizing compatibility with the existing Internet architecture. This includes the ability to use existing high performance routers, existing routing protocols, and existing number allocation policies. HIDRA is prototyped on a small network testbed and shown to work in a limited set of circumstances, including normal network operation, link failures, traffic engineering, and mixed “legacy” Internet and HIDRA topologies. The potential reduction of the Internet’s forwarding table is also analyzed.