An Active Approach to Measuring Routing Dynamics Induced by Autonomous Systems

The authors present an active measurement study of the routing dynamics induced by AS-path prepending, a common method for controlling the inbound traffic of a multi-homed ISP. Un-like other inter-domain inbound traffic engineering methods, AS-path prepending not only provides network resilience but does not increase routing table size. Unfortunately, ISPs often perform prepending on a trail-and-error basis, which can lead to suboptimal results and to a large amount of network churn. They study these effects by actively injecting prepended routes into the Internet routing system using the RIPE NCC RIS route collectors and observing the resulting changes from almost 200 publicly-accessible sources of BGP information.