Gathering Information on Other Sites Using WHOIS

Every domain legally registered with ICANN for use on the internet has a WHOIS database entry; by checking the WHOIS database, you can learn about the ownership and related details of other sites.

Why is WHOIS Useful?

As part of your strategic marketing activities for your private practice, you may from time to time find yourself researching competitors’ websites or other websites which for whatever reason are relevant to your work. Maybe someone writes to you requesting a link to their site, and you wonder who is behind their site…or you’re just peeking through some other site that you like (or don’t like) and want to know more about them. When you’d like to discover ownership information or related details for these other sites, the place to look is WHOIS, the database of information collected by registrars such as Network Solutions when they register a domain name.

How to Use WHOIS

Retrieving a WHOIS record for .com, .net, .org, .info, .biz, and .us domains is as easy as dropping by and entering the domain name in the query box on the front page. The official WHOIS service is actually run by InterNIC, but I find more useful, as it provides additional data which InterNIC does not.

WHOIS domain search.

Querying the WHOIS database

Similar search services are available for other top-level domains, such as Nominet for UK registered domains.

The results will provide all the basic information included in the WHOIS database, such as the details of the registrant, registrar, administrative and technical contacts; the nameservers which provide information on where traffic for that domain should be routed; and the dates of creation and next renewal for the domain. The results from (but not InterNIC) also include additional data such as site’s description and keywords, whether it has an SSL certificate, where it is listed in DMOZ, the specifics of the server software, the IP address and location, and more.

WHOIS results example.

Example results of a WHOIS search

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Caveats in Interpreting WHOIS Data

There are one or two caveats about interpreting WHOIS information, mostly relating to making sure that what you think you’re looking at really is what you’re looking at.

For example, many domain registrations are now either run through an anonymous offshore service or simply masked with one of many privacy services that registrars have begun selling. For the individual or company registering the domain, such services may cut down or eliminate unwanted approaches and unwanted spam. For the person researching the background on a website, they typically amount to something of a dead end for that specific route of finding ownership. Even if the displayed registrant details appear to be genuine and are not masked by a privacy service, the actual registrant may have any number of different relationships to the individual(s) actually running the site. The bottom line is: be cautious about inferring too much from what is written in the registrant fields.

Similarly, while the IP location may give a good indication of who is actually hosting a site, when this field of the results mentions a specific owner, this actually refers to who owns the range of IP addresses that includes the site’s IP. This may be the hosting company, or it may be the datacentre which houses the server — and these are two completely different things. Most experienced web sleuths will immediately recognize the names of major datacentres like The Planet or The Fortress ITX, but these or many others may trip you up. Years ago, a colleague eager to demonstrate his mastery of all things internet announced his authoritative conclusion that was hosted by such and such a company; however, that had nothing direct to do with hosting this site. They simply owned the datacentre and every IP address of every server housed within it. The moral of the story? Before you get too excited about what you think the WHOIS search may be telling you, be sure to check the facts!

The domain attached to the nameservers of a given site may also yield some clues to relationships between the domain you are researching and other service providers, but just as with the IP address information, caution is in order: nameservers may be run by the domain itself, by a third-party DNS provider, or by a hosting company.

Other caveats include the fact that the results of searches for some reason may fail to pick up whether a chained SSL certificate is installed on a server, and the number of other sites indicated as hosted on the same physical server may or may not have anything to do with the domain you are researching. (In shared hosting environments, one physical machine may host literally hundreds or even thousands of completely independent sites which have no relationship with one another whatsoever, except for sharing an IP address.)

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