Quantifying the Pitfalls of Traceroute in AS Connectivity Inference

Although traceroute has the potential to discover AS links that are invisible to existing BGP monitors, it is well known that the common approach for mapping router IP address to AS number (IP2AS) based on the longest prefix matching is highly error-prone. In this paper we conduct a systematic investigation into the potential errors of the IP2AS mapping for AS topology inference. In comparing traceroutederived AS paths and BGP AS paths, we take a novel approach of identifying mismatch fragments between each path pair. We then identify the origin and cause of each mismatch with a systematic set of tests based on publicly available data sets. Our results show that about 60% of mismatches are due to IP address sharing between peering BGP routers in neighboring ASes, and only about 14% of the mismatches are caused by the presence of IXPs, siblings, or prefixes with multiple origin ASes. This result helps clarify an argument that comes from previous work regarding the major cause of error...

• Type: Conference
• Year: 2010
• Where: PAM
• Authors: Yu Zhang, Ricardo V. Oliveira, Hongli Zhang, Lixia Zhang
• Keywords: AS Number, BGP AS Paths, Computer Networks, IP Address, PAM 2010