Comment by pocksuppet
13 hours ago
> 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.
> 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.
Ping a specific address of AS6939 and find out where it is.