title	excerpt	updated
Everything you need to know about DNS zone	Find out what a DNS zone does and what records it contains for a domain name	2024-06-17

Objective

DNS means Domain Name System and is a set of elements (DNS servers, DNS zones, etc.) that map a domain name to an IP address.

It is essential to differentiate between DNS servers and the DNS zone. A DNS zone is configured on the DNS server.

For a better understanding, we recommend reading our guide on Everything you need to know about DNS servers.

For example, when you want to access the domain.tld website via a web browser, your request is initially processed by this DNS set. This DNS set will then provide your web browser with the IP address of the server hosting the domain.tld website.

When you type domain.tld, the DNS servers associated with this domain name will be queried. These records contain the DNS zone of the domain.tld domain name, which contains the IP address of the domain.tld hosting plan. Your browser will then be able to display the domain.tld website contained on the web hosting plan. This is called a DNS resolution.

This guide explains what a DNS zone does, what it contains, and how it works with a domain name.

Instructions

Role of a DNS zone

A domain name’s DNS zone contains a configuration that can be applied to it. It consists of technical information, called DNS records. The DNS zone is a sort of referral center for a domain name.

For example, you can specify:

The IP address (DNS records of type A and AAAA) of your web hosting plan to display your website with your domain name.
The email servers (DNS records of type MX) to which your domain name must redirect the emails it receives.
Information related to the security/authentication of your services (web hosting, web server, email server, etc.) associated with your domain name (SPF, DKIM, DMARC DNS records, etc.).

A DNS zone is hosted on DNS servers. The DNS servers must be registered (with a domain name registrar) in order to use the DNS zone they host.

For more information, see our webpage explaining how a DNS server works.

DNS records

Various DNS record types exist. They all have a specific purpose in DNS resolution. At OVHcloud, they are divided into three parts:

Pointer records (A, AAAA, CNAME, DNAME, NS)
Email records (MX, SPF, DKIM, DMARC)
Extended records (TXT, SRV, CAA, NAPTR, LOC, SSHFP, TLSA)

Refer to our guide on DNS records for more information on the different types of records mentioned above. You will find elements that will allow you to better understand editing an OVHcloud DNS zone.

DNS zone example

To better represent what a DNS zone is, below is an example of a DNS zone hosted at OVHcloud for the domain name domain.tld. This is configured on the dns200.anycast.me and ns200.anycast.me OVHcloud DNS servers:

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In comparison, here is its equivalent in text mode:

$TTL 3600
@	IN SOA dns200.anycast.me. tech.ovh.net. (2024051800 86400 3600 3600000 60)
                 IN NS     ns200.anycast.me.
                 IN NS     dns200.anycast.me.
                 IN MX     1 mx1.mail.ovh.net.
                 IN MX     5 mx2.mail.ovh.net.
                 IN MX     10 mx3.mail.ovh.net.
                 IN A      203.0.113.0
www              IN A      203.0.113.0

In this example, the DNS zone specifies, among other things, the following information for DNS queries that reach it:

The DNS servers declared for the domain name domain.tld are the DNS servers dns200.anycast.me and ns200.anycast.me.
The server must return the IP address 203.0.113.0 if a DNS request is made to the domain name domain.tld or the subdomain www.domain.tld. For example, you can find the website domain.tld behind the IP address 203.0.113.0.
For emails, the DNS zone indicates that DNS queries made for @domain.tld email addresses must be sent to the mx1.mail.ovh.net server as a priority. If it takes too long to respond or is unavailable, the request will then be sent to the mx2.mail.ovh.net server, and so on until the last server that was declared mx3.mail.ovh.net.
The SOA (Start Of Authority) of the OVHcloud DNS zone indicates that the last update date of the DNS zone is 18/05/2024 and that the refresh time of the DNS zone is 3600 seconds. In DNS zones hosted elsewhere than at OVHcloud, the SOAs may contain other elements such as the email address of the DNS zone administrator. For security reasons, OVHcloud has chosen not to display this information in the SOA.