A fully qualified domain name (FQDN) is part of the Uniform Resource Locator (URL). As the name suggests, it is the full name of an entity within the framework of the Internet, including a host and a computer.
This article will explain the definition, examples, and functions of the fully qualified domain name. Then, we’ll walk you through how to find an FQDN on the three most commonly used operating systems: Windows, macOS, and Linux.
Examples of an FQDN
A fully qualified domain name,
also known as an absolute domain name, specifies all domain levels written in the format hostname.domain.tld. For example, a yahoo.com mail server would be mail.yahoo.com. Other examples include www.wordpress.org and news.bbc.co.uk.
You may also want to read our article that explains what a domain name is.
<img src="https://www.hostinger.co.uk/tutorials/wp-content/uploads/sites/2/2022/05/fqdn-01-1024×423.jpg" alt="The structure of a fully qualified domain name (FQDN
Let’s explore each element of an FQDN hierarchy
:
- Host name. It is a label assigned to a server service available on a network. A DNS server uses a host name to make an IP address easy to remember. Examples of a host name are “www” in www.hostinger.com and “en” in en.wikipedia.org.
- Subdomain. This part is located on the left side of a second-level domain and sometimes indicates a section of a larger domain. For example, support.hostinger.com is part of hostinger.com, and the word “support” is the subdomain. Note that not all domains have this element.
- A domain name. It consists of a second-level domain and a top-level domain (TLD). For example, in hostinger.com, “hostinger” is the second-level domain and “.com” is the TLD.
The maximum length of the host name and fully qualified domain name is
63 bytes per tag and 255 bytes per
FQDN.
What is
a partially qualified domain name? Like an FQDN, a
partially qualified domain name (PQDN) also indicates a web address, but only includes a host name or domain name
.
Generally, website developers configure the DNS of their sites to redirect visitors to the same page, whether they type the FQDN or PQDN.
For example, if you type hostinger.com or www.hostinger.com, you will arrive at https://hostinger.com, the URL of our homepage. PQDNs are usually favorable as they are shorter, which helps visitors find the site more easily.
When to use an FQDN FQDNs
are generally used in any interaction on the Internet, as they are easier to remember than IP addresses. Below are several scenarios of when to use an FQDN:
- Obtain an SSL certificate. A Secure Sockets Layer (SSL) secures a connection between a web server and a browser. An SSL certificate is issued for an FQDN, so you may not be able to use SSL services correctly without it.
- Connecting to a remote host. You can create a remote host or virtual machine by specifying any FQDN, which allows DNS to examine your DNS table and locate the server. If you use only the host name to connect to a server, the application might not be able to resolve the host name.
- Access to a specific domain service or protocol. Activities that transfer information over a network usually involve the DNS, including pointing to an FQDN. An example is when you connect to a file transfer protocol (FTP) or an email server.
- Migration to a new server. If you want to migrate the service to a server with a different IP address, using an FQDN instead of an IP address allows you to quickly change the DNS record and reduce interruptions in IP address changes.
Where to find an FQDN
Follow the steps below to find an FQDN on any desktop for Windows users:
- Go to the Start Menu button and type “device name”. Click the View your computer name menu.
- Select Advanced System Settings and you should see the Full Computer Name section: That’s the FQDN.
Alternatively, use a simple command by right-clicking on the Start menu and selecting Windows Terminal . Then, type the ipconfig /all command to reveal a complete Windows IP configuration, including the host name, primary DNS suffix, and connection-specific DNS suffix.
For macOS users, click the System Preferences icon in the Dock or navigate to the Apple menu at the top left, select System Preferences and choose Sharing.
At the top, you should see a connection-specific FQDN and DNS suffix in the Computer Name section.
Meanwhile, Linux users can find FQDN by entering the hostname -fqdn command line in the Terminal. To open the Terminal, press CTRL+ALT+T or search for it by clicking the Dash icon, typing “terminal” in the search box, and selecting the Terminal application.
Conclusion
A fully qualified domain name (
FQDN) allows a specific computer or server on the Internet to be uniquely identified within the Domain Name System (DNS).
This fully qualified domain name contains:
- Hostname subdomain
- if any
- Second-level
- TLD
- Final period
(
)
domain Top level domain (
)
Unlike fully qualified domain names,
including full levels of a domain, partially qualified domain names (PQDNs) consist only of the host name or domain name: a second-level domain and a domain extension. Since it’s shorter, a PQDN helps people remember direction much more quickly.
FQDNs are essential when you want to obtain an SSL certificate, migrate to a different server, or connect to a remote host or virtual machine. Where to find an FQDN will depend on your operating system. For example, Windows and Linux-based users can check it using Terminal, while Apple stores FQDNs in the System Preferences pane.
We hope this article helps you understand FQDN. If you’re planning to buy a domain name, be sure to check out our guide on how to buy a domain name. Let us know if you have any questions by leaving comments below.
