The Domain Name System (DNS) is used to connect IP addresses with websites names. With the help of DNS, web users can type in simple URLs, like 4psa.com, instead of long strings of numbers (known as IP addresses). The domain name is just the first step towards organizing the web for consumer use. Additional structures have been added for website administrators to make their website accessible. And one of these structures is the DNS zone.

A DNS zone is where you store name information about one or more domains you manage. You can divide your network into multiple subordinate zones to enable management, organization, or even speed. This guide will help you answer what is a DNS zone and what you should know about it so you can best optimize your website. 

What are DNS zones and records?

In the DNS, companies and people own websites and other pieces of digital real estate. A web admin might own the domain to one website, while also managing pages on other websites on the same server. This is where the DNS zone comes in. The zone associates these domains with specific people or organizations. This makes it easier to find content on specific servers because each individual domain is all within one zone.

A DNS zone is not the same as a domain, a zone can contain one or more domains. A DNS zone is usually kept on at least two geographically separated servers in order to provide redundancy. Instead, it is a parent category of the DNS and a subcategory of the server. For example, a single dedicated server can host up to thousands of websites.

DNS zones don’t need a lot of domains within them. In fact, many zones have only one domain. If a website is large or has high traffic levels, then it likely has its own. Similarly, if the website layout is complex or has a significant amount of data, it might need its own zone as well. Otherwise, multiple websites can be hosted under one DNS zone.

It’s a common mistake to associate DNS zones with domain names. This is especially true when one zone has only one domain. However, the DNS zone doesn’t highlight a particular domain or website. Instead, it labels the company or administrator that controls it. For example, a web administrator might keep all subdomains under one DNS zone except for one, which needs its own zone because of high traffic levels.

What is in a DNS zone file?

Every DNS zone has a definition that provides information on its contents. In most cases, a DNS zone is kept in a plain text file stored on the server. It can also be a binary file or a database, depending on the DNS application running on that server. This file lists each of the domain name records found in the zone to keep these various details organized.

Each zone file begins with a Start of Authority (SOA) record. This connects the zone to the administrator. It provides a name and an email contact in the event that the admin needs to be reached.

SOA records help with the versioning of the zone (serial number), primary DNS server that will handle the zone, with zone transfers and interrogation as it defines rules on how other servers interact with the DNS zone. The SOA record also contains information about record-keeping, like: Time to Live (TTL) value, REFRESH value, RETRY value, EXPIRE value. Such values include instructions for how records are kept in the DNS cache of other servers/clients. This allows for optimal data storage and makes it easy for users to access the information they need within a reasonable time frame. 

What are the DNS record types?

Each DNS zone has different DNS records that report relevant information. These records can be found in the DNS zone file on a server. The SOA is one type of record that’s associated with the DNS zone. However, there are other pieces of information that are just as relevant:

• The name server (NS) highlights which authoritative name server is associated with the domain. Along with the SOA record, these are the two necessary records in order to have a valid zone. 
• The mail exchange (MX) records determine which servers receive email messages to the domain. Most domains have two MX records with different priority levels so there’s always a backup option to receive mail.
• The A record reports the IPv4 address for the domain. You might also encounter AAAA for IPv6 addresses.
• The canonical name (CNAME) records the alias of one website for another. This could include a landing page that reroutes to the parent site or the information of a website that rebranded and changed its domain.
• TXT records hold human-readable information about the website. These records provide the ability to associate arbitrary text with a host or other name, such as human readable information about a server, network, data center, or other accounting information
• The server locator (SRV) records highlight the location of a service. This record isn’t frequently used, but there are a couple of services that can depend on it like the SIP server.

These record types have different levels of importance depending on your business. If you have a website with a simple landing page and contact form, then you’ll likely won’t have CNAME records. However, if you have an international business and eCommerce brand, you may need more advanced DNS records to record data about each website.

Most DNS administrators update zone and file information on an as-needed basis. For example, a website won’t have an SRV record until it needs one. On the other hand, every website will have an SOA and a NS record. Also, most of the websites will have an A record or AAAA record.

How do I find my DNS zone?

For the most part, you won’t need to check your DNS zone. However, there are times when you need to record your DNS or even change it. For example, if you buy a new domain, you will need to know its server information. You might even transfer information to a new server on occasion.

There are tools you can use to look up DNS information, including your DNS zone.You can use online tools that provide information about websites or whois/dig/nslookup and similar tools available on your operating system.

If you still aren’t sure how to find your DNS zone, talk to your site administrator. They can help you find your zone and pull your SOA. This can give you all the information you need about your website. Zone administrators are responsible for changing and updating DNS zones. This means if you’re the new administrator, this information should be provided to you by your predecessor.

If you use a hosting service for your server, they might be able to assist you in locating your DNS zone as well. They can also help you update your DNS information as you make changes to the domain or add new ones.

Know what’s important about your DNS zone

If you manage a website, then you have a DNS zone. By knowing it, you can control where your information is found and how you organize subdomains. This is particularly useful when your business starts to grow. If your website traffic increases or you need a new subdomain, you may need a second DNS zone. This can create a better web experience for your customers.

A web administrator will manage all these details for you. If you don’t have a web administrator, working with your hosting provider can be helpful in understanding your DNS zone and any changes that need to be made.

What’s more, if your hosting provider uses a DNS management and automation platform like DNS Manager, you will be able to manage your DNS zones and records by yourself from its friendly, web-based interface.