Measuring and Visualizing Interdomain Routing Dynamics with BGPath

The policy-oriented nature ofBGP provides network operators with great flexibility and control over the interdomain routing, nevertheless researchers showed that these benefits come at the cost of stability and predictability. In particular, policy interactions often separate, both in time and space, the effects of network events from their causes, making it hard to assess and debug network configurations. To better understand the complexity of BGP's behavior, we developed BGPATH, a publicly available tool that analyzes user-specified prefixes and relates their routing dynamics to the global Internet activity. Namely, BGPATH records data collected by distributed vantage points, checks the reliability of data sources, and evaluates the usage of each inter-AS link, both from a single and cross-vantage point perspective. The algorithms BGPATH relies on are shown to efficiently process huge streams of BGP data. We discuss time and space performance of these algorithms, underlining the potential to evolve towards a real-time system for BGP data measurement. BGPATH also provides the user with an effective visualization of the BGP activity related to a user-specified routing change, including contextual information which makes the analysis of the change less biased by BGP path exploration and outages of data sources. We exemplify the usefulness of our tool through a real usage scenario.