Understanding BGP Behavior through a Study of DoD Prefixes

BGP is the de-facto inter-domain routing protocol and it is essential to understand how well BGP performs in the Internet. As a step toward this understanding, this paper studies the routing performance of a sample set of prefixes owned by the U.S. Department of Defense (DoD). We examine how reliably the sample set is connected to the Internet and how it affects the rest of the Internet. We show that our sample set receives reliable connectivity, with the exception of a few prefixes. We also show that, on average, the sample set has minimal impact on global routing, but certain BGP features used by DoD routers result in periods of excessive routing overhead. During some stressful periods, our sample set, only 0.2% of all prefixes, contributed over 80% of a particular BGP update class. We explain how the BGP design allows certain local changes to propagate globally and amplifies the impact of our sample prefixes.