Internet Protocol (IP) addresses are locations on the Internet that identify a unique computer or local area network. A reverse lookup tells you information about the IP address, such as the name of the computer and the network it is on. You can perform a reverse lookup of an IP using reverse lookup tools found on the Internet.
Open your Web browser and visit http://remote.12dt.com/. Enter the Internet Protocol address you would like to perform a reverse lookup upon, then click "Lookup." The site will tell you the country, top level domain (TLD) and network name of the system.
Visit http://www.ipchecking.com/ in your browser and enter the IP address in the "IP Address or Host Name" field. Click "Lookup." You will be told the IPv4 and IPv6 address, network name, network type, originating company and ISP abuse address for the address. Additionally the site reports any spam blacklists databases that hold the IP address.
Navigate your browser to http://www.domaintools.com/research/reverse-IP/ and enter the IP address in the "IP Address or Domain Name" field. Click "Search." The reverse lookup on this site will tell you all associated domain names attached to the IP address. This search is useful to determine a list of sites hosted on an a single computer.