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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