What is a DNS NS record?

There are several types of records - or Resource Records as they are called - in the Domain Name System (DNS). This page explains what the NS record is and how it's used.

The purpose of a DNS NS record

The NS record allows you to delegate further DNS records to different nameservers.

The NS record stands for "nameserver".

Complex NS record structures are often used for very large domain names or organisations, where some (sub)domains can be delegated to different nameservers that are managed by different teams or technology stacks.

The structure of a DNS NS record

The NS records follow a similar, simple, structure like A or AAAA records.

ohdear.app.		3600	IN	NS	ns4.combell.net.
ohdear.app.		3600	IN	NS	ns3.combell.net.

This example indicates that DNS records for our domain should be found on either ns4.combell.net or ns3.combell.net. This is always "round robin", each nameserver has a similar weight or preference and can be chosen randomly.

Unlike MX records, where you can provide a priority or preference for those records, the NS records are always to be treated equal.

Special use cases of DNS NS records

The NS records allow you to delegate portions of your domain to other nameservers.

For instance, take the following example:

sub.domain.ohdear.app.		3600	IN	NS	ns1.otherprovider.tld.
sub.domain.ohdear.app.		3600	IN	NS	ns2.otherprovider.tld.

If a client wants to know where example.sub.domain.ohdear.app can be found, it'll have to walk up the DNS tree to find that all DNS queries for *.sub.domain.ohdear.app should be queried from one of the two NS records defined higher.

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