SI Lookup - Version 1.0 If you have a domain name, you can use one of the numerous Whois tools to determine its owner. Whois provides complete information about the owner of any domain name, up to the level of mailing addresses and telephone numbers. But what if you don’t have a domain name? What if all you have is a mere IP address? Or what if you don’t need information about the domain name, but are much more interested in who owns the Web server where it’s hosted?Quite often it is still possible to determine the owner, or, rather, the assignee, of an IP address. IP addresses in North America are assigned by ARIN, an independent, nonprofit corporation that provides IP registration. It is possible to unveil details about the organization that uses a particular IP address, or, to be precise, a block of IP addresses.There are no tools that come with Windows which can look up information about an IP address. Instead, you can visit ARIN database, learn about its query syntax,