[pocksuppet]

> How do you determine to whom an IP is even registered to?

You check the RIR's records.

> They get sub-leased all the time.

With records updated. If not, any consequences from wrong information fall on the lessor and lessee.

> There's also no way to actually know _where_ an IP actually originates from. Only its AS path.

Ping time from different locations on their upstream AS gives a good guess.

[sgjohnson]

> With records updated. If not, any consequences from wrong information fall on the lessor and lessee.

Not always + there are no consequences whatsoever.

Plenty of leasing services will just provide you with IRR & RPKI, without ever touching the actual records.

> Ping time from different locations on their upstream AS gives a good guess.

Upstream AS is meaningless if it's a T1 carrier. Ping AS6939. They are everywhere.

[pocksuppet]

Ping a specific address of AS6939 and find out where it is.

[icehawk]

ns1.he.net - 216.218.130.2, is simultaneously in

Texas (measured from Texas):

  8  port-channel13.core4.dal1.he.net (184.104.196.170)  1.830 ms  1.969 ms *
  9  ns1.he.net (216.218.130.2)  1.539 ms  1.560 ms  1.555 ms

Virginia (measured from Maryland):

  11  port-channel2.core1.ash1.he.net (184.105.222.174)  19.666 ms 24.395 ms *
  12  ns1.he.net (216.218.130.2)  16.748 ms  17.268 ms  20.507 ms

And California (measured from California):

  8  port-channel13.core1.fmt2.he.net (184.104.188.144)  3.830 ms be7.core1.sjc1.he.net (72.52.92.132)  5.197 ms port-channel13.core1.fmt2.he.net (184.104.188.144)  3.901 ms
  9  ns1.he.net (216.218.130.2)  2.600 ms  2.435 ms  2.728 ms

The speed of light doesn't lie, IP addresses don't have any sort of physicality.

[sgjohnson]

https://bgp.tools/as/6939#prefixes

They are everywhere. It's a global carrier. Carriers also know no geographic boundaries.