A developer recently published a new open-source command-line interface (CLI) tool designed to resolve IP addresses to geographical locations using network round-trip times. This project, detailed on blog.globalping.io, aims to replicate the accuracy achieved by dedicated geolocation providers like IPinfo by relying on empirical network measurements rather than potentially flawed public databases.
The impetus for the tool stems from observations that many VPN providers circumvent registration requirements by submitting incorrect location data to regional internet registries. The developer noted that established services often utilize extensive, distributed probe networks to accurately trace IP locations via latency analysis, a process that this new CLI attempts to democratize using the Globalping infrastructure.
Globalping, described as a community-powered project, allows users to host containerized probes that contribute to a public testing network exceeding three thousand nodes globally. The custom CLI tool utilizes this network, initially by pinging the target IP from probes across different continents to establish a regional baseline, which proved highly accurate even with only five probes per continent.
Further refinement involved switching the measurement protocol from standard ICMP ping, which is often blocked, to utilizing traceroute analysis. By examining the latency of the final reachable hop in the traceroute, the developer found a reliable method to accurately determine the country of origin, even when upstream networks restrict direct ICMP traffic.
When testing a known VPN IP that IPinfo reported as being located in Miami, the developer's tool successfully identified the location as Florida with very high confidence based on minimal latency readings. The process was subsequently extended to resolve city-level data, although the author acknowledged that city accuracy might correlate more closely with the nearest major network hub.
Despite the success, the developer indicated that a commercial-grade solution would require analyzing multiple protocols, potentially including TCP and UDP traceroutes across various ports, and incorporating ASN registration data for weighting accuracy. However, the current implementation provides a functional, low-latency alternative requiring minimal configuration.
The author suggests that users can run a substantial number of tests without authentication via the Globalping API, though registering for a free account enhances hourly testing limits. Hosting a personal probe is also presented as a pathway to generate passive testing credits for heavier usage.
