What is DNS Suffix?

DNS or Domain Name System is simply a mechanism that converts the human-readable hostnames into unique IP addresses that makes online communication possible. A DNS server consists of many parts, such as a DNS resolver, root server, TLD Server, and hostname.

If you are interested in learning more about the DNS in general, then refer to how the DNS works page. Once we have a clear understanding of DNS, then we can address the question that what exactly a DNS Suffix Is?

DNS Suffix – Explained

DNS suffix is the part of the complete DNS name that follows the allotted hostname. There could be multiple hostnames attached to a single DNS suffix.

To understand DNS Suffix, let’s take the domain name “support.google.com” as an example. This domain-only represents the suffix part of the entire DNS name. However, if we attach a hostname at the start, such as “john.support.google.com” then the “john” part will be referred to as hostname while the rest of the part will be called DNS Suffix.

If we dig deeper, then DNS Suffix is further classified into two major kinds that include:

  • Primary DNS Suffix
  • Connection-specific DNS Suffix

Primary DNS Suffix

As we already know, that DNS Suffix is the part without the hostname. A computer’s primary DNS suffix is based on what network or operating system technology tells it, including DHCP, Group Policy, or joining an Active Directory domain. If you are running a Windows computer, you can type “ipconfig /all” in the cmd, and the second line of the results will include your Primary DNS name.

Connection-Specific DNS Suffix

Typically, connection-specific DNS suffixes are associated with particular network interfaces. If you are performing DNS queries or DNS dynamic registrations, you can use it in addition to or in place of the Primary DNS suffix.

You can configure the connection-specific suffix manually by editing the interface properties or you can use DHCP option 15 for distributing it dynamically. DHCP Option 15 is commonly used with Windows.

Bottom Line

DNS is a complex subject because of various elements and servers included in the whole process. Still, DNS Suffix is easy to locate if you are aware of your hostname. If you want to check your DNS Suffix then simply remove the hostname part and you will be left with your required result.

However, if you need to learn more about DNS elements, then refer to this guide for a detailed explanation of its working and the mechanisms behind it.