RRLOC: A tool for iBGP Route Reflector topology planning and experimentation

The scalability of the global routing system is critical for the evolution of the Internet, and consequently, BGP scalability has been part of the Internet research agenda from long ago. The original concern was the growth of the routing table size, and more recently, the research community has also been considering the growth of the BGP churn, i.e. the number of messages that are generated by the BGP protocol. Some relevant studies have characterized the evolution of the external BGP (eBGP) churn for the last few years and have shown a moderated increase. There is evidence that part of such growth is caused by important changes in inter-AS connectivity patterns, along with some unexpected behaviour of internal BGP (iBGP), in particular, intra-AS duplication of BGP updates due to Route Reflectors (RR). There are many vantage points in the Internet that record BGP traces, which permit to study eBGP behaviour, but there exist no public iBGP traces nor internal AS topology repositories, limiting the exploration of iBGP influence in the global scalability problem. In this paper we analyse route reflection benefits and caveats, and present RRLOC, an Open Source tool developed to facilitate research on this matter. The tool supports the location of Route Reflectors in a given AS topology using well-known algorithms, enabling the experimentation on iBGP dynamics, with the aid of network simulators. It also allows network planners to test different scenarios for RR placement.