Leveraging BGP Dynamics to Reverse-Engineer Routing Policies

Inter-domain routing policies are an important component of today’s routing infrastructure. Knowledge about these policies can be used for better traffic engineering, detecting misconfiguration, preventing policy conflicts and also, in understanding Internet routing. However, many domains consider their policies proprietary and rarely reveal them. Hence, techniques that reverse-engineer routing policies are very useful. Existing approaches infer routing policies primarily by analyzing routing tables. In this paper, we describe how inter-domain routing dynamics, primarily the BGP convergence process, can be leveraged to infer route selection policies of domains. We discuss the results of using our proposed technique with archived BGP protocol data. We also describe the applicability of our proposed technique in achieving better traffic engineering and detecting policy conflicts.