IP addresses on computer networks do not represent specific geographic locations. It is still theoretically possible, however, to determine the physical location of IP addresses in many (but not all) cases.
An IP Address Is a Georeference
Geolocation systems attempt to map IP addresses to geographic locations using large computer databases. Some geolocation databases are available for sale, and some can be searched for free online.
Geolocation systems generally function for their intended purposes but also suffer from some important limitations.
How Is IP Address Location Used?
Geolocation proves useful in several different cases:Manage Websites: Website creators use a geolocation service to track the geographic distribution of visitors to their site. Besides satisfying general curiosity, advanced web sites dynamically change the content shown to each visitor based on their location. These sites may block access to visitors from certain countries or locales.Find Spammers: Individuals being harassed online often trace the IP address of the email or instant messages.Enforce the Law: The Recording Industry Association of America and other agencies may use geolocation to find people who illegally swap media files on the internet, although typically they work directly with internet service providers.
What Are the Limitations of Geolocation?
IP address location databases have greatly improved in accuracy over the years. They may attempt to map each network address to a specific postal address or latitude and longitude coordinate. However, various limitations still exist:IP addresses may be associated with the wrong location (for example, the wrong postal code, city, or suburb within a metropolitan area).Addresses may be associated only with a broad geographic area (such as a large city or a state). Many addresses are associated only with a city, not with a street address or latitude and longitude location.Some addresses do not appear in the database and therefore cannot be mapped (often true for IP numbers not commonly used on the internet).
Can WHOIS Be Used for Geolocation?
The WHOIS database was not designed to locate IP addresses geographically. WHOIS tracks the owner of an IP address range (subnet or block) and the owner's postal address. However, these networks may be deployed in a different location than that of the owning entity. In the case of addresses owned by corporations, addresses also tend to be distributed across many different branch offices.
While the WHOIS system works well to find and contact owners of websites, it is not effective for geolocating the site's servers or users.
Where Are Some Geolocation Databases?
Several online services allow you to search for the geographic location of an IP address by entering it into a simple web form. Two popular services are Geobytes and IP2Location. Each of these services uses proprietary databases of addresses based on internet traffic flow and website registrations. The databases were designed for use by web site creators and can be purchased as a downloadable package for that purpose.
What Is Skyhook?
A company named Skyhook Wireless built a geolocation database of a different kind. Their system is designed to capture the Global Positioning System location of home network routers and wireless access points, which may also include residential street addresses. The Skyhook system is not publicly available.
What About Hotspot Databases?
Thousands of wireless hotspots serve public connections around the world. Various online databases find Wi-Fi hotspots by mapping the hotspot location including its street address. These systems work well for travelers seeking internet access. However, hotspot finders provide only the network name of the access point and not its actual IP address.