DNS Record types

[[DNS]] record types are used to map domain names to IP addresses and other information. Here are some of the main DNS record types and their descriptions:

A

Also known as an address record, it maps a domain name to an [[IPv4]] address. This is the most common type of DNS record and is used to point a domain name to an IP address. For example, an A record for the domain name example.com could be example.com. IN A 192.0.2.1.

AAAA

Also known as an IPv6 address record, it maps a domain name to an [[IPv6]] address. This record is used to point a domain name to an IPv6 address. For example, an AAAA record for the domain name example.com could be example.com. IN AAAA 2001:db8::1.

ALIAS

An ALIAS record is a virtual record type that provides CNAME-like behavior on [[apex domains]]. It maps a domain name to a hostname instead of an IP address. For example, if your domain is example.com and you want it to point to a hostname like myapp.herokuapp.com, you can't use a CNAME record, but you can use an ALIAS record. The ALIAS record will automatically resolve your domain to one or more A records at resolution time, and resolvers see your domain as if it had A records.

CAA

Also known as a certification authority authorization record, it specifies which [[certificate authorities]] are authorized to issue certificates for a domain name. This record is used to prevent unauthorized certificate issuance and improve security. For example, a CAA record for the domain name example.com could be example.com. IN CAA 0 issue "ca.example.com".

CNAME

Also known as a canonical name record, it maps an alias name to a true domain name. This record is used to create an alias for a domain name. For example, a CNAME record for the domain name www.example.com could be www.example.com. IN CNAME example.com.

DNSKEY

Also known as a DNS security key record, it stores a public key used to verify [[DNSSEC signatures]]. This record is used to authenticate DNS data and prevent [[DNS spoofing]]. For example, a DNSKEY record for the domain name example.com could be example.com. IN DNSKEY 256 3 8 AwEAAc....

DS

Also known as a delegation signer record, it stores a hash of a DNSKEY record in the parent zone. This record is used to authenticate child zones and prevent [[DNS cache poisoning]].

MX

Also known as a mail exchange record, it maps a domain name to a list of mail exchange servers. This record is used to specify the mail server responsible for accepting email messages on behalf of a domain name. For example, an MX record for the domain name example.com could be example.com. IN MX 10 mail.example.com.

NAPTR

Also known as a naming authority pointer record, it maps a domain name to a regular expression that can be used to transform the domain name into another domain name. This record is used to support advanced services such as ENUM.

NS

Also known as a name server record, it maps a domain name to a list of name servers. This record is used to delegate a domain name to a set of name servers. For example, an NS record for the domain name example.com could be example.com. IN NS ns1.example.com.

PTR

Also known as a pointer record, it maps an IP address to a domain name. This record is used to perform a reverse [[DNS lookup]]. For example, a PTR record for the IP address 192.0.2.1 could be 1.2.0.192.in-addr.arpa. IN PTR example.com.

SOA

Also known as a start of authority record, it contains administrative information about a [[DNS zone]]. This record is used to specify the primary name server for a DNS zone and other administrative information. For example, an SOA record for the domain name example.com could be example.com. IN SOA ns1.example.com. admin.example.com. 2019020101 3600 1800 604800 86400.

SRV

Also known as a service record, it maps a domain name to the hostname and port number of servers for a specific service. This record is used to locate services such as SIP and XMPP1. For example, an SRV record for the domain name _sip._tcp.example.com could be _sip._tcp.example.com. IN SRV 10 60 5060 sipserver.example.com.

SSHFP

Also known as a Secure Shell fingerprint record, it maps a domain name to the fingerprint of an [[SSH]] public key. This record is used to authenticate SSH connections.

TLSA

Also known as a [[tls]] authentication record, it maps a domain name to the certificate or public key of a server. This record is used to authenticate the server’s identity and establish a secure connection. For example, a TLSA record for the domain name _443._tcp.example.com could be _443._tcp.example.com. IN TLSA 3 1 1 abcd....

TXT

Also known as a text record, it contains text information about a domain name. This record is used to store arbitrary text data in a DNS record. For example, a TXT record for the domain name example.com could be example.com. IN TXT "v=spf1 a mx ip4:192.0.2.0/24 ~all".