The Whois utility built into Port Explorer may initially look like a relatively small utility, but don't let looks deceive you - it is a powerful search engine client that gives you full 100% unrestricted access to the domain registry database servers of the world, and best of all it's easy to use thanks to a built-in intelligent automatic search feature.

Domain registry database servers (Whois servers) are Internet servers that run a Whois service on TCP port 43, providing free instant information to anything that sends it a query. Port Explorer's Whois client allows you to search all of these databases to find information about domains, domain owners, IP addresses, companies and more. Information returned from the Whois server can often include things such as the address owner, owner's title, contact phone number, postal address, email address and more.

There are many competing registrars and each one only hosts information about domains that are registered through it. For example, .au (Australian) domains are registered through aunic (http://www.aunic.net). Thus, to search for information on a .au domain, you need to send your query to the aunic server (whois.aunic.net). Most countries have a single Whois server, but some have multiple servers, each handling a different second-level domain (2LD). The .com/.net/.org domains are different because these domains have been deregulated, and now competing registrars hold the Whois information for those domains that are registered with it. The best way to search for a .com/.net/.org domain is to send your query to whois.internic.net, which will then refer the Whois client to the appropriate Whois server that handles the domain or address you requested. Port Explorer's Whois client supports automatic referral and multi-referral transfer.

To find out about the flags a server will accept and all its legal information, just select the Whois server you want to know more about and just enter "?" or "help" as your search query.

Please note that it is not possible to obtain Whois database information on all domains and addresses as there are no laws that require that information to be present. Additionally, many Whois databases are only updated monthly, so it can be harder to obtain information about brand new domains.

Automatic Search - Recommended for most search queries
As outlined above there is no single Whois server to send all your search queries to, and with a complex system of competing registrars, custom database formats, server referrals and other quirks, how do you know which server to start at? With the Automatic search built into Port Explorer's Whois utility, you don't need to worry about any of that - simply type in a domain or IP address to connect to and press Enter on your keyboard, or press the Search button to activate the search. We've worked hard on the Automatic search feature to ensure that it is as reliable as possible - it rarely fails, and Automatic Search may be the only search you'll ever need to use.

When Whois is activated from the right-click popup menu on the main display window, the IP address query automatically goes to whois.arin.net by default. If the address is in the form of a host then it will automatically use Automatic Search.

Manual Search - Recommended for advanced users should Automatic search fail to yield results
Manual searching allows you to send any query to any Whois server in the world. For example, the microsoft.com domain is registered with Network Solutions, so you can directly go to whois.networksolutions.com simply by selecting Other in the server list and typing in the Whois server address in the textbox that becomes visible.

Most Whois servers accept flags with the search query. Accepted flags will usually be told to you in the output display. Sometimes putting an "=" sign before the hostname is needed to specify all the records of the name you gave.

On some servers you can also search on peoples names just by putting in the name of the person you are searching for. It usually has to be "last name, first name" or just "last name" format to work.

Legal note - Please be aware that when you submit queries to Whois servers, you are agreeing to their Terms of Use. To display the terms of use, simply search for "?" or "help" at any Whois server. Generally speaking, most Terms of Use simply outline that you shouldn't use the information provided by Whois servers for any unlawful purposes or for the purpose of advertising. Please do the right thing, respect and abide by their Terms of Use - they're providing you with a wealth of free information after all and if the system is abused then its future could be jeopardised.