That’s why MaxMind charges for more accurate data. It requires actual effort...

Yes, which is the whole point of my question: how is this data compiled?

Just because it requires effort does not mean it can't be done in an open source way.

1) Agreements with ISPs [most accurate]

2) IP Spidering via traceroutes / RIPE/etc data.

3) Agreements with third parties that have IP/Address mapping due to data supplied from users. [least accurate]

That'd be my guess anyway.

They also have a form on their site to submit corrections. Maxmind's db is so prevalent now, I suspect (indirect) users submit all the info they need nowadays.

They are likely using various information, like addresses from RIPE etc.

But there's also a NSA patent on this topic, "Method for geolocating logical network addresses" (filed in 2000).

https://patents.google.com/patent/US6947978B2/en?oq=6%2c947%...

Oddly enough, that patent apparently expired today?

> Oddly enough, that patent apparently expired today?

Not anymore, maybe they are reading HN as well :-)

    2023-09-15 - Adjusted expiration
  > 2019-12-09 - Application status is Expired - Fee Related
    2005-09-20 - Publication of US6947978B2
    2005-09-20 - Application granted
    2002-07-04 - Publication of US20020087666A1
    2000-12-29 - Assigned to GOVERNMENT OF THE UNITED STATES, AS REPRESENTED BY DIR. NAT. SECURITY AGENCY, THE NSA GENERAL COUNSEL (IP&T)
    2000-12-29 - Priority to US09/752,898
    2000-12-29 - Application filed by National Security Agency

Can't edit, but the last item is always just its status at the current day. My bad.

Interesting, I thought government agencies couldn't get patents and trademarks because technically we own everything they do.

Country-level data can be obtained from the 5 RIRs freely and via a standardized CSV-like document updated every day. I wrote an article about that, the first part shows how to get and parse that: https://www.ecalamia.com/blog/make-your-own-geoip-api/