Add DNS record sets

  • 2 minutes

It's important to understand the difference between DNS record sets and individual DNS records. A DNS record set (also known as a resource record set) is a collection of records in a DNS zone.

You define record sets in the Azure portal. The configuration settings depend on the record type for the set to create.

Suppose you choose to create a set of A records (or Address record) to identify IP addresses associated with your domain. To create the A records, you need to provide the TTL (time to live) and the IP addresses. The TTL value specifies how long each record is cached by clients.

Screenshot that shows how to add a DNS record set in the Azure portal.

Things to know about DNS record sets

Let's examine some characteristics of DNS record sets.

  • All records in a DNS record set must have the same name and the same record type.

    Consider the following example where we have two records in a record set. All records have the same name, www.contoso.com.. All records have the same record type, A. Each record in the set has a different value. In this case, each record provides a different IP address.

    www.contoso.com.        3600    IN    A     134.170.185.46
www.contoso.com.        3600    IN    A     134.170.188.221

  • A DNS record set can't contain two identical records.

  • A record set of type CNAME can contain only one record.

    A CNAME record (or Canonical name record) provides an alias of one domain name to another. This record is used to provide another name for your domain. The DNS lookup operation tries to find your domain by retrying the lookup with the other name specified in the CNAME record.

  • You can create a record set that doesn't have any records. This set is called an empty record set.

  • If you have an empty record set for your domain, this set doesn't appear on your Azure DNS name servers.