Fully Qualified Domain Name (FQDN): Definition And Examples

While you may be familiar with registering a domain name like yoursite.com for your website, when you type an address into your browser or send an email, you’re technically relying on a Fully Qualified Domain Name (FQDN). An FQDN goes a step further by providing the exact, complete address that a device or service needs to be found on the Internet. This guide explains what FQDNs are, how they work, why they differ from standard domain names, and provides examples to help you understand their role in domain management.

KEY TAKEAWAYS

• A Fully Qualified Domain Name is the complete address that identifies a server or website and shows exactly where it is located within the DNS system.
• FQDNs ensure the DNS delivers the correct response, enabling access to websites, servers, email, and other online resources.
• Full domain names are used everywhere to accurately and reliably identify servers, websites, and networks, as well as for site security.
• Configuring an FQDN involves registering a domain name, creating DNS records in zone files to map specific services to your FQDNs, and ongoing management.
• Finding your device’s or website’s FQDN is easy and helps with securely configuring networks, software, and remote access.

Understanding Fully Qualified Domain Names

A Fully Qualified Domain Name (FQDN) is the complete name used to identify and specify the exact location of a web server or website in the Domain Name System (DNS). A good way to remember it is that it’s like giving a full street address instead of just a city name; www.example.com is a complete address, whereas example.com is the domain name most people are familiar with.

An FQDN, sometimes called an absolute domain name, is read from right to left, moving from the most general to the most specific domain levels. Here’s an example of what it’s made up of using www.shop.yoursite.com:

• Root: The final dot (often hidden)
• Top-Level Domain (TLD): .com
• Second-Level Domain (SLD): yoursite
• Subdomain: shop
• Hostname: www

Each part of an FQDN contributes to identifying a specific web address in the DNS hierarchy. Together, they create a unique path that the DNS can translate (resolve), ensuring it directs requests to the correct web service or device.

They are essentially the backbone of internet communication, enabling everything from accessing websites to sending emails. This includes being components of email addresses, e.g., name@mailserver.example.com, web addresses (often hidden but implied in URLs), and for setting up secure connections using SSL (Secure Sockets Layer) certificates.

It’s also worth mentioning that a Partially Qualified Domain Name (PQDN) is a hostname or domain name that doesn’t include all the labels up to the root. In simpler terms, it’s not a complete domain name that needs additional context (usually a DNS suffix) to be resolved into a fully qualified address. These are generally used for internal or Local Area Networks (LANs), not connecting to remote hosts.

How FQDNs Interact with the Domain Name System

The DNS is the system that translates the domain names we type into browsers into IP (Internet Protocol) addresses such as 192.0.1.2. FQDNs provide the necessary details for the system to store and query.

Every full domain maps to a set of DNS records, like A records (IP addresses), MX records (email servers), and CNAMEs (domain aliases). These records are stored in zone files and DNS tables, which are managed by authoritative name servers.

Here’s how the process works:

When you type the URL (Uniform Resource Locator) shop.yoursite.com into a web browser address bar, your browser doesn’t know the corresponding numerical IP address directly. Instead, it sends a query to a DNS server.

The resolver begins by asking the root servers for information about the TLD, in this case, .com. Root servers don’t know the IP address for shop.yoursite.com, but they do know which name servers are authoritative for the .com TLD, and the resolver is then directed to them.

The .com name servers then point to the name servers responsible for yoursite.com. This process continues down the DNS hierarchy until it reaches the one for yoursite.com that holds the actual IP address mapping for shop.yoursite.com.

FQDNs also enable access to web hosting servers, databases, FTP (File Transfer Protocol) services, cloud services, and other Internet resources.

Examples of What FDQNs are Used for

Fully qualified domain names are essential for various online tasks. Without them, websites, domain services, security, and network communications would not work reliably or at all. Below are a few use cases:

Browsing & Website Access

When you type www.randomwebsite.com into your browser, you are using an FQDN. This directs your browser to the specific web server hosting the main website. Similarly, blog.randomwebsite.com would lead you to that specific subdomain.

Email Services

In an email address like yourname@mail.example.com, the mail.example.com part is the FQDN. The DNS (specifically MX records) uses it to find the correct mail server responsible for receiving emails for the example.com domain name, so your message reaches the right inbox.

SSL Certificates

SSL/TLS (Transport Layer Security) certificates are essential for security. An SSL issued for an FQDN, such as secure.example.com, ensures that all data transfers are encrypted. If you try to access example.com (without “secure” as part of the domain) and it has a different certificate, a browser warning will appear, because the certificate is strictly for its full domain name, so you connect to the correct, secure site.

Firewall Configuration

When configuring a firewall, you can restrict connections, so your browser can only access specific websites or block malicious sites. Using the FQDN instead of an IP address improves security because website IPs can change. The FQDN allows the firewall to resolve to the new IP automatically.

Remote Access & File Transfer

Connecting to remote servers often relies on FQDNs. For example, when using a VPN (Virtual Private Network) to access network resources securely, you typically connect to its FQDN, such as vpn.yourcompany.net. Similarly, if you’re using an FTP server to upload or download files, you’d point your client to its FQDN, such as ftp.yourcompany.net. This ensures you’re connecting to the correct, authorized server for secure access, network management, and file transfers.

DNS Records

When you look up a DNS record, the record itself is associated with an FQDN. For instance, an A record maps an FQDN (www.example.com) to an IP address. A CNAME record maps one FQDN (blog.example.com.) to another FQDN (pages.hostingprovider.com.).

You can also use them to improve your Search Engine Optimization (SEO) rankings by making your website more visible in search results.

How to Configure Your Fully Qualified Domain Name

Setting up a Fully Qualified Domain Name involves a series of steps that tie together domain registration and DNS configuration. Here’s a breakdown of how to configure your FQDNs using the Hosted.com® control panel.

Register a Domain Name

The first step is to get your domain name. This means registering an SLD such as yourcompany.com. This gives you the exclusive right to use that specific domain setup, which forms the core of any FQDNs you will create later.

Set Up DNS Records & Zone Files

Next, you’ll need to tell the internet how to find specific items on your domain, such as your website or email. You do this by configuring DNS records in your domain’s zone file, which can be accessed in the Zone Editor in the cPanel dashboard. The zone file is a database on a DNS server that holds all the information for your domain.

You’ll usually create an A (Address) record for each specific service or site you want to identify. For example, to make www.yourcompany.com point to your web server, you’d create an A record mapping www.yourcompany.com to the hosting server’s IP address.

Similarly, you might want to create an A record for mail.yourcompany.com that points to your mail server’s IP address, as well as an MX (Mail Exchange) record. CNAME (Canonical Name) records are also common, allowing you to create domain aliases.

Lastly, you’ll link your new FQDNs to your services. This means ensuring that your web and mail servers, virtual machines, and any others are configured to respond correctly and are accessible.

Finding Your FQDN

Understanding FQDNs is one thing, but how do you actually find them? The method depends on whether you’re looking for the FQDN of a specific computer, a server, or a website.

Check System Settings

For your PC name, the FQDN is usually the full device name combined with your local network’s domain.

If you use Windows, you can often find it by right-clicking This PC or My Computer and selecting Properties, or by going to the Start Menu and clicking Settings > System > About. Look for the Device name and the Full computer name.

Alternatively, if you are familiar with it, you can use the Command Prompt for a direct DNS query, which will show the name and its corresponding IP address.

On macOS, go to System Settings > General > About. Your computer’s name is listed there. If it’s part of a network domain, the FQDN would combine this name with the domain.

Web Hosting Control Panel

If you’re looking for a website or server FQDN, the information is managed by your hosting provider, and you will find it in your web hosting control panel.

The FQDN for both is simply your domain name itself, often with the www. prefix. You can confirm this in your web hosting control panel, like cPanel. You can also use online DNS lookup tools to help find them, along with their associated DNS records.

FAQS

Other Blogs of Interest

– What Is A Domain Manager? Everything You Need To Know

– Domain Security: Best Practices

– What Are Dropped Domains and How To Buy Them

– Cheap Domain Registrar: What to Look For

– Hosted.com® NEW AI Domain Name Generator Is Here