[reincoder]

Well, we do have more than 700 servers pinging everything we can, but in a very respectful manner (https://ipinfo.io/blog/probe-network-how-we-make-sure-our-da...). There is no special packet type or anything; it is just pings. Our volume is much much lower. We avoid doing anything that could annoy anyone. We just take the RTT and triangulate the IP location.

[coderholic]

We also tag all our traffic with greynoise: https://viz.greynoise.io/query/actor:%22IPinfo.io%22

[cedws]

How accurately can you triangulate an IP?

[reincoder]

Accuracy is difficult to measure, but ours is the best in the industry because we use active measurement. We verify our IP geolocation data with voluntary device location data backed by GPS coordinates, but putting a universal figure on the accuracy is quite difficult.

Based on the RTT to each IP address from a server, we essentially draw radii on the world map. Now, as we ping that IP address from other servers, we can draw more of these radii. From the overlapping areas between these server RTT radii, we can now estimate where the IP address could be. So, in general, areas where we have a high density of servers usually have the highest location granularity.

Now, with 720 servers, these overlapping areas get quite small and reach zip code level accuracy for wired IPv4 addresses. For data centers and larger offices, it goes to geographic coordinate levels sometimes. But for carrier IP IPv6 addresses, consistent city-level accuracy is what we usually aim for.

The data is continuously getting better as we add more probe servers. Currently, from public information, in terms of location diversity, our server network infrastructure is larger than Cloudflare's and any commercial VPN service out there. And we are looking for more servers to add (https://forms.gle/kNYr2MBL8zRPgNrJ8).