1. What is IP-based Geolocation?
IP-based Geolocation is the mapping of an IP address or MAC address to the real-world geographic location of an Internet-connected computing or a mobile device. Geolocation involves mapping IP addresses to the country, region (city), latitude/longitude, ISP, and domain name among other useful things.
2. Where can I get an IP-based Geolocation database?
There are several commercially available geolocation databases, and their pricing and accuracy may vary. Ip2location, MaxMind, Tamo Soft, DB-IP, Ipinfo, and IPligence offer fee-based databases that can be easily integrated into a web application. Most geolocation database vendors offer APIs and example codes (in ASP, PHP, .NET, and Java programming languages) that can be used to retrieve geolocation data from the database. We use several commercial databases to offer free geolocation data on our website.
There are also freely available geolocation databases. Vendors offering commercial geolocation databases also offer a Lite or Community edition that provides IP-to-Country mappings. Ip2Country.net and Webhosting.info (Directi) offer free IP-to-Country databases that can be also integrated into your web application. There are companies also offering free web services that can be used to show the geolocation of an IP address on your website.
3. How accurate is IP-based Geolocation?
The accuracy of the geolocation database varies depending on which database you use. For IP-to-country databases, some vendors claim to offer 98% to 99% accuracy although typical Ip2Country database accuracy is more like 95%. For IP-to-Region (or City), accuracy range anywhere from 50% to 75% if neighboring cities are treated as correct. Considering that there is no official source of IP-to-Region information, 50+% accuracy is pretty good.
4. How does IP-based geolocation work?
ARIN Whois database provides a mechanism for finding contact and registration information for IP resources registered with ARIN. The IP whois information is available for free, and determining the country from this database is relatively easy. When an organization requires a block of IP addresses, a request is submitted, and allocated IP addresses are assigned to a requested ISP.
