Scalability considerations for an anomaly-free iBGP routing

Scalability is an important aspect when spreading externally learned routing information via the Border Gateway Protocol within Autonomous Systems. However, research showed that common iBGP scalability techniques like Route Reflection and AS Confederations are involved with anomalies in general. These unwanted effects can be inherently avoided by providing routers with individual sets of routing information. Implementing a modified iBGP routing information exchange in productive systems requires a scalability which is comparable to conventional techniques. Our studies show that providing routers with suitable individual information should not cause any serious decline at this point: While the most crucial parameters proved to be not problematic, only the number of paths managed by routers turn out to be hard to predict. Hence, we examine this parameter for the productive system of a large Service Provider, showing only irrelevant increases. Our results indicate that this approach could be an alternative for future iBGP routing architectures.