Resilient Routing under Hierarchical Automatic Addressing

BGP table size and update rate have increased dramatically in the last decade. The rate of the growth poses great demand on memory size and CPU speed of the router control processor. Hierarchical Automatic Addressing (HAA) reduces BGP table size and update rate by enabling prefix aggregation for multihomed ASes. However, the aggregation blocks routing information of individual ASes, and causes the routing system fails to react to failures. In this paper, we propose a resilient routing protocol referred to as Routing with Detour (RD) to address the problem. RD provides resilient routing under HAA, and it reacts to failures in a timely manner without modifying BGP. Our experiments with realistic AS topology show that RD has slight impact on HAA´s performance. More precisely, HAA with RD can reduce BGP table size and update rate by more than 90%.