Can I find where a Web site visitor is located by their IP address?
It’s sometimes possible to determine the location of an IP host. The brute force approach is to perform a reverse DNS lookup of the domain containing the IP address and extrapolating from the whois information to create an educated guess about where the host is located.
This method, though, isn’t foolproof. Many organizations have widely distributed global networks registered and managed from a central location. RFC 1876 describes a more comprehensive way to associate DNS records with geographical locations, called DNS LOC. This provides the means to include latitude and longitude information directly in DNS database entries.
Published in 1996, RFC 1876 defines DNS LOC, which isn’t implemented as widely as it could be. Depending on DNS LOC information being present in other organizations’ DNS records may not be completely reliable, but tools are in place to include location information for your own DNS, and to map host locations for those whose DNS records contain the DNS LOC information.
Useful Web sites on this topic include www.caida.org, www.ckdhr.com/dns-loc, www.geobytes.com and www.maxmind.com, which provide reference and research information, as well as products and services that go beyond DNS LOC to provide detailed geographical information about Web site visitor IP addresses.
