I have a database with about two million entries (!), relating IP ranges to locations. Unfortunately, a lot of the data is overlapping, so that every IP produces multiple hits (about two or three. Of these, only one is within an acceptable range of error. I have tried with about 10 IPs, and it seems the last one is always the most accurate, but I would like to try with more, about a thousand before making such a general rule and weeding out stuff by it.
Is there anywhere I can get such a massive number of accurate IP addresses, complete with location information?
Is there a better way of cleaning this data?