I've wanted to try something like this before, but I was under the impression that providers like MaxMind might use other techniques to figure out the "real" location of a server.
ipinfo.io uses a probe network for this[1], but even then a server physically located in the Netherlands with an IP announced as being from, say, Seychelles would still respond to pings faster from a European location than from somewhere like Singapore (unless you go out of your way to induce latency to ICMP responses).
Thank you for mentioning us. I work for IPinfo. We perform a combination of a ping and a traceroute to understand how packets travel through the internet so that we can determine the location of the IP address. Our objective is to map the entire internet.
However, ideally, we should have a PoP in Seychelles. Some of our recent expansions have been in offshore territories.
ipinfo.io uses a probe network for this[1], but even then a server physically located in the Netherlands with an IP announced as being from, say, Seychelles would still respond to pings faster from a European location than from somewhere like Singapore (unless you go out of your way to induce latency to ICMP responses).
[1] https://ipinfo.io/blog/probe-network-how-we-make-sure-our-da...