Record Set Types and Configuration Rules

Type

Table 1 describes the record set types.

Table 1 Record set types

Record Set Type

Scenario

Description

A

Public and private zones

Maps domains to IPv4 addresses.

CNAME

Public and private zones

Maps one domain name to another or multiple domain names to one domain name.

MX

Public and private zones

Maps domain names to email servers.

AAAA

Public and private zones

Maps domain names to IPv6 addresses.

TXT

Public and private zones

Specifies text records. It is usually used in the following scenarios:

  • To record DKIM public keys to prevent email fraud.
  • To record the identity of domain name owners to facilitate domain name retrieval.

SRV

Public and private zones

Records servers providing specific services.

NS

Public and private zones

Delegates subdomains to other name servers.

  • For public zones, an NS record set is automatically created, and you can add NS record sets for subdomains.
  • For private zones, an NS record set is automatically created, and you cannot add other NS record sets.

SOA

Public and private zones

Specifies the master authoritative DNS server for a domain name. The SOA record set is created by the system and cannot be added manually.

CAA

Public zone

Grants certificate issuing permissions to CAs. CAA record sets can be used to prevent the issuance of unauthorized HTTPS certificates.

PTR

Private zone

Maps IP addresses to domain names.

Record Set Configuration

Table 2 lists the value requirements for different types of record sets.

Table 2 Requirements for record set values

Record Set Type

Value

Example

A

IPv4 addresses mapped to the domain name

You can enter a maximum of 50 record values, each on a separate line.

192.168.12.2

192.168.12.3

CNAME

Domain name alias. You can enter only one domain name.

www.example.com

MX

Email server address

You can enter a maximum of 50 record values, each on a separate line.

The format is [priority][mail server host name].

Configuration rules:
  • priority: priority for an email server to receive emails. A smaller value indicates a higher priority.
  • mail server host name: domain name provided by the email service provider

10 mailserver.example.com.

20 mailserver2.example.com.

AAAA

IPv6 addresses mapped to the domain name

You can enter a maximum of 50 record values, each on a separate line.

ff03:0db8:85a3:0:0:8a2e:0370:7334

TXT

Text content

Configuration rules:

  • Text record values must be enclosed in double quotation marks.
  • One or more text record values are supported, each on a separate line.

    A maximum of 50 text record values can be entered.

  • A single text record value can contain multiple character strings, each of which is double quoted and separated from others using a space.

    One character string cannot exceed 255 characters.

    A value must not exceed 4096 characters.

  • The value cannot be left blank.
  • The text cannot contain a backslash (\).
  • Single text record:

    "aaa"

  • Multiple text records:

    "bbb"

    "ccc"

  • A text record that contains multiple strings:

    "ddd" "eee" "fff"

SRV

Server address

You can enter a maximum of 50 record values, each on a separate line.

The value format is [priority] [weight] [port number] [server address].

Configuration rules:

  • The priority, weight, and port number range from 0 to 65535.
  • A smaller priority value indicates a higher priority.
  • A larger weight value indicates a larger weight.
  • The server address is the domain name of the target server.

    Ensure that the domain name can be resolved.

NOTE:

The system checks the priority values first. If the priority values are the same, the system will check the weight values.

2 1 2355 example_server.test.com

NS

DNS server address

You can enter a maximum of 50 record values, each on a separate line.

ns1.example.net

ns2.example.net

CAA

CA to be authorized to issue certificates for a domain name or its subdomains

You can enter a maximum of 50 record values, each on a separate line.

The format is [flag] [tag] [value].

Configuration rules:

  • flag: certificate authority (CA) identifier, which is an unsigned character ranging from 0 to 255. Usually, the value is set to 0.
  • tag: a string of 1 to 15 characters composed of letters and digits from 0 to 9. The tag can be one of the following:
    • issue: authorizes CAs to issue all types of certificates.
    • issuewild: authorizes CAs to issue wildcard certificates.
    • iodef: requests notifications once CAs receive invalid certificate requests.
  • value: authorized CA or email address/URL required for notification once the CA receives invalid certificate requests, depending on the value of tag. The value must be enclosed in quotation marks (""). It is a string of 1 to 255 characters, including letters, digits, spaces, and special characters -#*?&_~=:;.@+^/!%

0 issue "ca.abc.com"

0 issuewild "ca.def.com"

0 iodef "mailto:admin@domain.com"

0 iodef "http:// domain.com/log/"

PTR

Private domain name mapped to the private IP address. You can enter only one domain name.

www.example.com.
Parent topic: Record Set