FQDN – What is it and when to use it?

FQDN is an essential part of the Domain Name System. If you want to learn more about it, you are in the right place. In this article, we will see what it means and why it is important. 

FQDN – meaning

The term “Fully Qualified Domain Name,” or FQDN for short, is a domain name that specifies its exact location in the Domain Name System’s tree structure. It is also sometimes referred to as an absolute domain name. Every domain level, including the top-level domain and the root zone, is specified. It is the most thorough method of composing a specific domain name for a host or device.

Learn more about FQDN & What is PQDN?

A Fully Qualified Domain Name (FQDN) has the following syntax: hostname. domain name. TLD. An example is info.doodledns.com or mail.doodledns.net.

The FQDN’s structure

Fully Qualified Domain Name, from right to left, has the following structure:

  1. The root label, often known as the “root” of the DNS system, is at the highest hierarchical level. Only a period or a dot is used to express it. It is no longer necessary to enter this dot when using the browser’s search function. So, It will be added by the browser.
  2. The Top Level Domain is the next highest hierarchical level ( “.com,” “.org,”, “.net,”, etc.) 
  3. The Domain is at the next level of the hierarchy. It’s a unique name that a company owner has picked. 
  4. The last one is the hostname, also known as Subdomain. It is the lowest label and displays many subcategories or services, such as postal or retail.

What is the purpose of the FQDN?

  • You’ll need the FQDN to get an IP address and set up DNS. Otherwise, to connect your PC to the Internet.
  • To make use of remote access. Because your device will be the server, it will require a name (FQDN) and an IP address in order to perform Internet services.
  • To obtain a secure socket layer (SSL) certificate. You’ll need one of these certificates to protect communication between your site and its visitors, and you’ll need an FQDN to do it.

How to check it?

It is really easy to check your device’s FQDN. But, first, follow the steps outlined below.

  • On a macOs and Linux

Run the Terminal program. Write to the following command, and press the Enter:

“hostname -f” 

Then the information about FQDN will appear.

In addition, on Linux, you can use the following command:

“hostname -fqdn” 

  • On Windows

Click the Windows “Start” button and find the Windows command prompt. Type:

 “ping -a IP” 

where “IP” is the IP address for the computer. Press “Enter.” Then the information about FQDN will appear.


In conclusion, we can say that FQDN is really useful. To locate the exact location of a host, you’ll need exactly a Fully Qualified Domain Name. It is a precise identifier, and computers require it for a variety of functions.

Leave a Reply

Your email address will not be published. Required fields are marked *