How to Resolve IP Aliases
Neil T. Spring, Mira Dontcheva, Maya Rodrig, David J. Wetherall · 2008
To construct accurate Internet maps, traceroute-based mapping efforts must group interface IP addresses into routers, a task known as alias resolution. In this paper, we introduce two new alias resolution approaches based on inference to handle addresses that cannot be resolved by existing methods based on probe measurements. The first decodes the DNS names assigned by the ISP to recognize the name fragments that identify a router. The second infers aliases from the graph of linked IP addresses and requires no additional measurement traffic. We then experiment with feasible combinations of these techniques and existing ones by resolving aliases during the mapping of PlanetLab, a large wide-area overlay, and UUnet, a large ISP. We find that these techniques have complementary strengths and weaknesses and are best used in concert. The DNS and graph inference methods provide information where existing probe methods fail and are less dependent on router implementation choices. The existing probe methods can be made more effective in practice by using multiple vantage points and taking advantage of implementation synergies.