When learning how to bring your website online, you will inevitably come across the WHOIS lookup service. It is a searchable database of every domain name currently registered in the world. Even if you haven't heard the term, it's a good idea to learn a little more.
What exactly is a WHOIS lookup, and why would I use it?
WHOIS, is a free public database, and a search service which allows a user to search through and view the publicly listed information, associated with an already registered domain name. WHOIS is regulated by ICANN. This information is passed to the registry database, by your registrar when you register a domain name with them.
A WHOIS search will return no results or registration information if a domain is not yet registered with a registrar, and is available for public registration.
The first reason, therefore, that you might want to use the WHOIS service, is to check if a domain is available for registration, before choosing a name for your website.
Note: While looking for a domain name, you can also use the cloudmatrix domain name search option here: https://www.cloudmatrix.co.za/cart.php?a=add&domain=register
Another reason might be that you want to report abuse to the website or domain administrator, or get in touch with a website owner.
Why does the WHOIS database exist?
At its inception, the database was meant simply as a domain directory, listing the contact information of anyone transmitting data over the initial stages of what is now the internet.
This was before the advent of search engines.
What specific information is stored in the WHOIS database?
As a domain name is registered the registrant (probably you) has to supply contact information.
This information must be accurate and true because if you supply false information when registering your domain name you could have your domain suspended or cancelled, as per ICANN policy.
Registrant information includes:
Name.
Address.
Phone Number.
Email Address.
Nameserver.
Wait, so my information is public on WHOIS?
Yes. By default, every registered domain is required to have specific details about; the registrant, the registrar, the technical and abuse contacts, the domain guardian or registrant email address, the nameservers, etc.
However, some of this information can now be hidden, since ICANN released the option to obfuscate (hide) sensitive public information. This is normally an additional service that can be purchased from your domain registrar or hosting provider.
How to perform a WHOIS Lookup.
There are a few ways to perform a WHOIS lookup. We'll cover:
- WHOIS online services through a web browser,
- From a Linux command line with the 'whois' command.
WHOIS online service.
The best source of WHOIS information is obviously ICANN themselves. Simply point your browser to their Registration data lookup tool here: https://lookup.icann.org/en
Enter a domain name you want to search, and click on the Lookup button.
Complete the captcha and view the results.
Note: ICANN lookup does not support .co.za domain names. For this you would have previously needed to use South Africa's dedicated WHOIS lookup (whois.co.za), which now appears to be defunct. For now you may need to use a command line option, as below.
You could also try one of the following online WHOIS services:
WHOIS from the Linux command line.
From a Linux terminal run the command (using cloudmatrix.co.za as an example).
# whois cloudmatrix.co.za
The command prompt will return all of the public information available for this domain.
If you don't have the whois command installed on your machine, simple run:
# sudo apt update && sudo apt upgrade
Then run the following command to install the command before running it again as in step one.
# sudo apt install whois
Conclusion
You've learned about what the WHOIS database is, how to search it and why you might want to.