----- Original Message ----- From: "william(at)elan.net" <william@elan.net> To: "Jim McBurnett" <jim@tgasolutions.com> Cc: <nanog@merit.edu> Sent: Monday, June 13, 2005 2:55 PM Subject: RE: IP->Country Data (RE: ISP's Contact List)
On Mon, 13 Jun 2005, Jim McBurnett wrote:
I'm sure that this made it here before but:
www.analysespider.com/ip2country/ip_country.html
Commercial service when there are several free ones available....
BTW - based on what I can see they are not updating data once per day but only once/month. Also having some experience in this matter I highly doubt that its much more accurate then what I got - it appears no matter what path you take to get the data, it would to a degree be wrong (difference being which part is wrong). One possible way to resolve some issues could be to have testing servers placed in several locations and analyze TTL for connections to various ips to determine how far its from several servers - of course it would also not be accurate as ip networks are not necessarily interconnecting in the same region (CAIDA did their best with this method some time ago but have not kept updated data as far as I know).
the most accurate systems i am aware of use online purchase statistical data to increase accuracy. someone purchases a blue widget online, from a certain ip address and with a credit card with a certain billing zip code, and voila - they now have an idea of where that ip might be. of course, this works best (only?) for residential ip addresses in broadband-enabled neighbourhoods, but it's pretty darn good at telling me where i am (within 5-10 miles). -p