John Heidemann

Verfploeter: Broad and Load-Aware Anycast Mapping

TitleVerfploeter: Broad and Load-Aware Anycast Mapping
Publication TypeTechnical Report
Year of Publication2017
AuthorsW. B. de Vries, R. O. de Schmidt, W. Hardaker, J. Heidemann, P. - T. de Boer, and A. Pras
Date Publishedmay

IP anycast provides DNS operators and CDNs with automatic fail-over and reduced latency by breaking the Internet into \emphcatchments, each served by a different anycast site. Unfortunately, \emphunderstanding and \emphpredicting changes to catchments as sites are added or removed has been challenging. Current tools such as RIPE Atlas or commercial equivalents map from thousands of vantage points (VPs), but their coverage can be inconsistent around the globe. This paper proposes \emphVerfploeter, a new method that maps anycast catchments using active probing. Verfploeter provides around 3.8M virtual VPs, $430\times$ the 9k physical VPs in RIPE Atlas, providing coverage of the vast majority of networks around the globe. We then add load information from prior service logs to provide calibrated predictions of anycast changes. Verfploeter has been used to evaluate the new anycast for B-Root, and we also report its use of a 9-site anycast testbed. We show that the greater coverage made possible by Verfploeter's active probing is necessary to see routing differences in regions that have sparse coverage from RIPE Atlas, like South America and China.