Empirical Evaluation for the Impact of Core-Edge Separation on Internet Routing Scalability

BGP is the de facto standard protocol for the inter-domain routing. Due to multi-homing and traffic engineering, the BGP routing table size of default free zone (DFZ) is growing rapidly. Inter-domain routing is facing the scaling challenge. Such routing scaling issue has being concerned by research community and IETF, and many solutions have been proposed. Among them, the core-edge separation scheme gets more attentions than others due to its practical advantages. The typical core-edge separation solutions include LISP, eFIT, Ivip, etc. They prevent edge network specific prefixes from entering into transit core, and reduce the DFZ BGP routing table size. However, there has no evaluation on how much scalability can be improved from core-edge separation. In this paper, we use real BGP routing data of Routeviews Project to empirically analyze the possible impacts of core-edge separation. We find that it can reduce 43% routing table size and prevent more than half of announcement and withdraw messages.