DNS Resource Record Types

Learn about the different types of DNS records.

The DNS uses resource records to describe properties of domains in the DNS system. Because there are multiple services and protocols used on the internet, we also need different types of resource records (we already saw the A and NS types in the last lesson).

The following fields are common for all resource records:

Common Resource Record Fields

Field

Meaning

owner

The owner field is also often referred to as name and reflects the domain name (owner) to which this resource record belongs to.

TTL

TTL stands for time-to-live and refers to how long a resource record can be cached.

class

This is the class of the record. There are only two options, IN and CH. IN stands for internet system and CN for Chaos system. CN is still part of the RFC 1034 specification but is not used in practice.

type

This is the type of the record (e.g., A or NS)

RDATA

The RDATA field is also often referred to as the value of a resource record. The content depends on the type of the resource record.

If we take a look at the output of one of our dig commands from the last lesson, we can see these fields reflected in the ANSWER, AUTHORITY or ADDITIONAL section:

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owner TTL class type RDATA
educative.io. 3600 IN NS mario.ns.cloudflare.com.

Let’s take a look at the most important types of resource records.

NS record

The NS records describe the name servers responsible for a particular domain. The resource record above is an example of an NS ...