On the Impact of Filters on Analyzing Prefix Reachability in the Internet
The reachability of IP address prefixes exhibits significant fluctuations due to changes in both physical connectivity and ISP routing policies. In the late 1990s, Labovitz et al. performed an extensive study of inter-domain path stability by analyzing BGP routing data. To reduce the noise in the BGP data, e.g., transient updates during route convergence, they applied several filters to preprocess the raw BGP data. In this paper, the authors investigate prefix reachability as advertised by BGP, while revisiting the preprocessing filter design problem. They show that the reachability analysis results are highly sensitive to the specific filters applied and the parameters that control the strength of the filters.