Replication: 20 Years of Inferring Interdomain Routing Policies

In 2003, Wang and Gao [67] presented an algorithm to infer and characterize routing policies as this knowledge could be valuable in predicting and debugging routing paths. They used their algorithm to measure the phenomenon of selectively announced prefixes, in which, ASes would announce their prefixes to specific providers to manipulate incoming traffic. Since 2003, the Internet has evolved from a hierarchical graph, to a flat and dense structure. Despite 20 years of extensive research since that seminal work, the impact of these topological changes on routing policies is still blurred. In this paper we conduct a replicability study of the Wang and Gao paper [67], to shed light on the evolution and the current state of selectively announced prefixes. We show that selective announcements are persistent, not only across time, but also across networks. Moreover, we observe that neighbors of different AS relationships may be assigned with the same local preference values, and path selection is not as heavily dependent on AS relationships as it used to be. Our results highlight the need for BGP policy inference to be conducted as a high-periodicity process to account for the dynamic nature of AS connectivity and the derived policies.