| author | ms.service | ms.topic | ms.date | ms.author |
|---|---|---|---|---|
vhorne |
azure-dns |
include |
11/04/2024 |
victorh |
In Azure DNS, records are specified by using relative names. A fully qualified domain name (FQDN) includes the zone name, whereas a relative name doesn't. For example, the relative record name www in the zone contoso.com gives the fully qualified record name www.contoso.com.
An apex record is a DNS record at the root (or apex) of a DNS zone. For example, in the DNS zone contoso.com, an apex record also has the fully qualified name contoso.com (this is sometimes called a naked domain). By convention, the relative name '@' is used to represent apex records.
Each DNS record has a name and a type. Records are organized into various types according to the data they contain. The most common type is an 'A' record, which maps a name to an IPv4 address. Another common type is an 'MX' record, which maps a name to a mail server.
Azure DNS supports all common DNS record types: A, AAAA, CAA, CNAME, MX, NS, PTR, SOA, SRV, and TXT. Note that SPF records are represented using TXT records.
Additional record types are supported if the zone is signed with DNS Security Extensions (DNSSEC), such as Delegation Signer (DS) and Transport Layer Security Authentication (TLSA) resource records.
DNSSEC resource record types such as DNSKEY, RRSIG, and NSEC3 records are added automatically when a zone is signed with DNSSEC. These types of DNSSEC resource records can't be created or modified after zone signing.
Sometimes you need to create more than one DNS record with a given name and type. For example, suppose the 'www.contoso.com' web site is hosted on two different IP addresses. The website requires two different A records, one for each IP address. Here's an example of a record set:
www.contoso.com. 3600 IN A 134.170.185.46
www.contoso.com. 3600 IN A 134.170.188.221
Azure DNS manages all DNS records using record sets. A record set (also known as a resource record set) is the collection of DNS records in a zone that have the same name and are of the same type. Most record sets contain a single record. However, examples like the one above, in which a record set contains more than one record, aren't uncommon.
For example, suppose you have already created an A record 'www' in the zone 'contoso.com', pointing to the IP address '134.170.185.46' (the first record above). To create the second record you would add that record to the existing record set, rather than create an additional record set.
The SOA and CNAME record types are exceptions. The DNS standards don't permit multiple records with the same name for these types, therefore these record sets can only contain a single record.