Refining IP-to-AS Mappings for AS-Level Traceroute

It is of great significance for network operators and researchers to obtain accurate AS-level traceroute paths, for which mapping IP addresses to correct AS numbers is critical. Thus, there have been a lot of efforts to improve the original IP-to-AS mapping table, which was extracted from BGP routing tables. One of these efforts is called pair matching, which refines the original mapping table by maximizing the number of matched pairs of traceroute and BGP AS paths. However, the existing pair-matching-based methods refine the original IP-to-AS mapping table only with the prefix granularity, i.e., IP addresses in the same /24 prefix are mapped to the same AS or the same set of ASes, which does not fit reality. In this paper, we attempt to refine the IP-to-AS mapping table with the IP address granularity, i.e., allowing IP addresses in the same prefix to be mapped to different ASes. The results show that our fine-grained method can produce a more accurate IP-to-AS mapping table. In addition, this paper also provides a better understanding for the pair-matching-based methods.