What is a DNS Zone? Master and Slave DNS Zone and how to create it.

What is a DNS zone

First, let us explain what a DNS zone is. DNS zone is a container of DNS settings and DNS records of a DNS namespace. The DNS namespace can have single or multiple DNS zones, each managed by a particular DNS host/service. This division helps for the administrative purposes. It is like an enormous pie, each piece of it allows better separation of the administrative load and helps with redundancy.

Don’t directly associate a DNS zone with a specific domain. A DNS zone may contain multiple domain names or a single one; the important thing is that it is used for controlling a fraction of the namespace. DNS zones can be on the same servers too.

We also recommend that you read “ What is Authoritative DNS server? “

Different types of DNS zones

There are different types of DNS zones, but in this article, we will set our eyes on just two:
* Master (Primary) DNS zone
* Slave (Secondary) DNS zone

Master DNS zone

Master zones, contain a read/write copy of the zone data. There could be only one Master zone on one DNS server at a time. All the DNS records added manually or automatically, are written in this Master zone of the DNS server.
The data is stored in a standard text file — .txt. The advantage is that it is easy to back it up and to recover in case of problems.
Something essential is that to be able to make changes to the DNS zone, the master zone must be available. If the server with your Primary DNS is down, you won’t be able to make any changes.
If you want to have redundancy, you must have the zone data accessible on multiple servers.

If you want to learn how to create a Master zone in ClouDNS, check the following step-by-step tutorial:

1. Click on the sign-in button and enter your email address and your password. Once you have logged in, you will see your Dashboard. From the list, you will notice that you do not have any registered DNS zones.
2. Click on the “Add new” button. In the pop-up window, click on “Master zone”. You can create your DNS zone with the NS records you want. However, we recommend you to use the suggested ones.
3. In the text field, enter your domain name without HTTP, HTTPS, or WWW. Example: yourdomain.com. Once you do it, click on the “CREATE” button.

You have successfully created your Master DNS zone. From the top menu, you will be able to manage your Master DNS zone with all of the available options. Here you will see all the DNS records you can create and use for your needs. From the list, you can see your hostname, the type of the record, where they are pointed to, and what the TTL is.

You can also check our wiki page about Master DNS zone.

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Slave DNS zone

The Slave zone is a read-only copy of the zone data. Most of the times Slave DNS zones are copies of Master zones. They can also be copies of other Slave zones or Active Directory Zones.
If you try to change a DNS record on a Secondary zone, it can redirect you to another zone with read/write access. By itself, it can’t change it.
One of the primary purposes of a Slave zone is to serve as a backup. When the master zone is down, it can still answer requests for the zone from its copy.

Check the following step-by-step tutorial to learn how to create a Slave Zone in ClouDNS.

1. Click on the sign-in button and enter your email address and your password.
2. Once you have logged in, you will see your Dashboard. From the list, you will notice that you do not have any registered DNS.
3. Click on the “Add new” button and then click on “Slave/Backup zone”
4. In the first field, enter your domain name without HTTP, HTTPS, or WWW. Example: yourdomain.com. In the second field, on the right, add the IP address of your Master Server. Once you do it, click on the “Add Slave” button.

You have successfully created your Slave DNS zone. From the top menu, you will see the available options for your Slave Zone. Here is also the IP address of your Master Server.

If you want to use Slave DNS zones, you can also review our Secondary DNS page, and decide which of our premium plans is right for you.

Now you know what a DNS zone is and the difference between these two types — Master DNS zone and Slave DNS zone. For any additional questions about your DNS infrastructure, you can contact our customer support.

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Originally published at ClouDNS Blog on February, 2020.