A Study of Geolocation Databases

TL;DR

This paper evaluates the accuracy of IP geolocation databases by grouping approximately 100,000 IP addresses worldwide into PoPs to analyze their strengths, weaknesses, and anomalies in location mapping.

Contribution

It introduces a novel grouping algorithm based on structure and delay to assess geolocation database accuracy at large scale.

Findings

High confidence in IP grouping accuracy

Identification of database weaknesses and anomalies

Insights into geolocation database reliability

Abstract

The geographical location of Internet IP addresses has an importance both for academic research and commercial applications. Thus, both commercial and academic databases and tools are available for mapping IP addresses to geographic locations. Evaluating the accuracy of these mapping services is complex since obtaining diverse large scale ground truth is very hard. In this work we evaluate mapping services using an algorithm that groups IP addresses to PoPs, based on structure and delay. This way we are able to group close to 100,000 IP addresses world wide into groups that are known to share a geo-location with high confidence. We provide insight into the strength and weaknesses of IP geolocation databases, and discuss their accuracy and encountered anomalies.