The disclosed method and system increase routing efficiency by identifying a set of candidate Autonomous Systems (ASes) able to reduce average AS distances towards a set of target ASes. Starting from a list of Routing Information Base (RIB) snapshots and a set of target ASes, candidate ASes are ranked based on the gain they would provide in terms of AS distance if they were connected to the network administrator AS. A set of starting ASes may represent the ASes to which the administrator is already connected, and a set of forbidden ASes may represent the ASes to which the administrator does not want to connect. An exemplary web-based interface may show gains of candidate ASes, allowing the administrator to better understand how much an average AS distance toward the set of target ASes would improve.