Resolving IP Aliases in Building Traceroute-Based Internet Maps

Alias resolution, the task of identifying IP addresses belonging to the same router, is an important step in building traceroute-based Internet topology maps. Inaccuracies in alias resolution affect the representativeness of constructed topology maps. This in turn affects the conclusions derived from studies that use these maps. This paper presents two complementary studies on alias resolution. First, we present an experimental study to demonstrate the impact of alias resolution on topology measurement studies. Then, we introduce an alias resolution approach called analytic and probe-based alias resolver (APAR). APAR consists of an analytical component and a probe-based component. Given a set of path traces, the analytical component utilizes the common IP address assignment scheme to infer IP aliases. The probe-based component introduces a minimal probing overhead to improve the accuracy of APAR. Compared to the existing state-of-the-art tool ally, APAR uses an orthogonal approach to resolve a large number of IP aliases that ally fails to identify. Our extensive verification study on sample data sets shows that our approach is effective in resolving many aliases with good accuracy. Our evaluations also indicate that the two approaches (ally and APAR) should be used together to maximize the success of the alias resolution process.