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titleClick here to view records for forward DNS zones.


Record TypeDetails
IP Address (A)

Maps a hostname to a 32-bit IPv4 address.

Type A rules have the following format:

hostname. IN A XXX.XXX.XXX.XXX

where:

  • XXX.XXX.XXX.XXX is the IP address for the hostname.
  • hostname. is the zone name or one of its subdomains.

Examples:

Code Block
domain.com. IN A 1.2.3.4
subdomain.domain.com. IN A 1.2.3.4
domain.com. IN A [IP]

Click here for more info on this type of record.

AAAA Record (AAAA)

Maps a hostname to a 128-bit IPv6 address.

AAAA rules have the following format:

hostname. IN AAAA:AAAA:AAAA:AAAA:AAAA:AAAA:AAAA:AAAA

where:

  • AAA:AAAA:AAAA:AAAA:AAAA:AAAA:AAAA:AAAA is the IPv6 address for the hostname.
  • hostname. is the zone name or one of its subdomains.

Examples:

Code Block
domain.com. IN AAAA abcd:1234:ffff:0:12:3:ab1:aa
subdomain.domain.com. IN AAAA abcd:1234:ffff:0:12:3:ab1:aa

Click here for more info on this type of record.

Certification Authority Authorization (CAA)

Specifies one or more Certification Authorities (CAs) authorized to issue certificates for that domain.

CAA rules have the following format:

hostname. IN CAA flags tag value

where:

  • flags is an unsigned integer between 0 and 255. It is currently used to represent the critical flag, that has a specific meaning per RFC.
  • tag is an ASCII string that represents the identifier of the property represented by the record
  • value is the value associated with the tag.

The CAA record consists of a flags byte and a tag-value pair referred to as a ‘property’. Multiple properties may be associated with the same domain name by publishing multiple CAA records at that domain name.


There are 3 available tags:

  • issue: explicity authorizes a single certificate authority to issue a certificate (any type) for the hostname.
  • issuewild: explicity authorizes a single certificate authority to issue a wildcard certificate (and only wildcard) for the hostname.
  • iodef: specifies a URL to which a certificate authority may report policy violations.

Examples:

Code Block
example.com. IN CAA 0 issue ";"
example.com. CAA 0 issue "letsencrypt.org"
example.com. CAA 0 issuewild "comodoca.com"
example.com. CAA 0 iodef "mailto:example@example.com"


Alias for record (CNAME)

Canonical name record is an alias (or nickname) of one name to another.

The A record to which the alias points can be either local or remote - on a foreign name server. This is useful when running multiple services (like an FTP and a webserver) from a single IP address.

Each service can then have its own entry in DNS (like ftp.example.com. and www.example.com.). It is also used when running multiple HTTP servers, with different names, on the same physical host.

CNAME rules have the following format:

hostname. IN CNAME servername.

where:

  • hostname. is the zone name or one of its subdomains
  • servername. is a fully qualified domain name (FQDN) either inside or outside the zone.

Examples:

Code Block
ftp.domain.com. IN CNAME inside.domain.com.
ftp1.domain.com IN CNAME outside.zone.com.
k1._domainkey.domain.com IN CNAME dkim.zone.com.

RFC 1034 states: “If a CNAME record is present at a node, no other data should be present; this ensures that the data for a canonical name and its aliases cannot be different.” In order for these requirements to be met in DNS Manager, the value specified in the Zone alias name field of the CNAME record cannot be set for the DNS Zone name filed in NS, A, AAAA, SRV, CNAME and TXT records or for the Zone email field in an MX record.

Click here for more info on this type of record.

Nameserver (NS)

Maps a domain name to a list of DNS servers authoritative for that domain. Delegations depend on NS records.

NS rules have the following format:

hostname. IN NS servername.

where:

  • hostname. is the zone name or one of its subdomains
  • servername. is a domain name which specifies an

authoritative host for the specified hostname.

Examples:

Code Block
domain.com. IN NS ns1.example.com.
domain.com. IN NS ns2.example.com.

The NS records of $ORIGIN are displayed in bold characters. DNS Manager allows to choose in the interface which is the primary nameserver on a zone (required for some local TLDs). In order to set up an NS record as primary check Make primary when you add/edit the desired NS record.

For BIND to take a DNS zone into consideration, at least one NS record must be defined for $ORIGIN in the respective zone.

For best practice, it is recommended to have at least two NS records defined for each public domain.

Click here for more info on this type of record.

Mail exchanger (MX)

Maps a domain name to a list of mail exchange servers for that domain.

MX rules have the following format:

hostname. IN MX preference servername.

where:

  • hostname. is the zone name or one of its subdomains
  • preference indicates the hostname's priority. The lower the preference,
    the higher the priority. This parameter accepts values between 0 and 50.
  • servername. is a fully qualified domain name (FQDN) inside the zone

Examples:

Code Block
mail.domain.com. IN MX 10 domain.com.
webmail.domain.com. IN MX 5 domain.com.

Click here for more info on this type of record.

Text record (TXT)

Allows an administrator to insert arbitrary text into a DNS record. This has been used to implement new functions with DNS support without allocating new record types. For example, this record is used to implement the Sender Policy Framework and DomainKeys specifications.

TXT rules have the following format:

hostname. IN TXT "Text information"

where:

  • hostname. is the zone name or one of its subdomains
  • "Text information" can be any type of string including strings generated by SPF Rules

Examples:

Code Block
domain.com. IN TXT "k=rsa; p=MEwwDQYerwqEWwE"
subdomain.domain.com. IN TXT "this is a test"

Click here for more info on this type of record.

Service Record (SRV)

Specifies the location of the server(s) for a specific protocol and domain.

SRV rules have the following format:

_Service._Protocol.Hostname. IN SRV TTL Priority Weight Port Target

where:

  • Service is the symbolic name of the desired service. You can find a list of the available services at http://www.dns-sd.org/ServiceTypes.html.
  • Protocol is the protocol of the desired service. This is usually TCP or UDP, but 4PSA DNS Manager supports all the protocols listed here http://www.iana.org/assignments/protocol-numbers.
  • Hostname. is the domain name for which the record is valid.
  • TTL is the standard DNS time to live field. If there is no TTL specified for the record, the TTL value for the zone will be employed.
  • Priority is the priority of the target host. The lower the value, the
    higher the priority level.

  • Weight indicates a relative weight between records with the same
    priority.

  • Port is the port on which the service is to be found.

  • Target is the domain name of the target host.

    The Target parameter can not be an alias (CNAME). When Target is set to . the service is unavailable.

Examples:

Code Block
_service._tcp.domain.com. IN SRV 0 1 9 subdomain.domain.com.
*._tcp.domain.com. IN SRV 0 0 0 . 

on TCP protocol

Click here for more info on this type of record.

NAPTR record (NAPTR)

Naming Authority Pointers.

NAPTR rules have the following format:

order preference services flag regexp replacement

where:

  • order indicates the order in which records are to be processed when a query returns multiple NAPTR records
  • preference indicates the processing order for multiple records with identical order
  • services indicate the resolution protocol and resolution services employed when applying a rewrite according to the regexp or replacement field
  • flag is a modifier that affects the next DNS lookup
  • regexp is the primary field used for rewrite rules
  • replacement is a secondary field used for rewrite rules

Examples:

Code Block
domain.com. IN NAPTR 100 10 "u" "sip+E2U" "!^.*$! sip:information@foo.se!i" .
subdomain.domain.com. IN NAPTR 102 10 "u" "smtp+E2U" "!^.*$! mailto:information@foo.se!i" .

Click here for more info on this type of record.


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