BGP Routing Table: Trends and Challenges
Alexander Afanasyev, Neil Tilley, Brent Longstaff, Lixia Zhang · 2009
BGP is currently the most important protocol for ensuring global connectivity over the Internet. This puts a great deal of responsibility on BGP and creates a number of challenges for it. Of primary concern is the impact that various currently deployed BGP-based techniques have on the scalability of the global routing table. While these techniques provide ISPs with additional traffic management services (e.g., balancing, multi-homing, etc), they have expanded the routing table size at a pace that exceeds the allocation rate and is increasing. In our study we present a two-level analysis of BGP announcements for the period 2003–2009. First, we correlate IP allocation data with globally announced prefixes and show how efficiently ISPs announce their allocated address space. Second, we correlate BGP announcement data to itself and show various internal factors that contribute to routing table growth. Finally, we document in which regions of the world routing announcements have originated during the period of this study, and we draw conclusions about the spread of global Internet connectivity.