List of DNS record types
A Resource Record (RR ) is the basic unit of information in the Domain Name System (DNS). It occurs in ASCII format on in zone files or in compressed form in DNA transport packets and DNS caches. Some RR types - so-called pseudo - resource records - only be used in DNS transport packets.
RR format in Zone Files
The format shown here is based on the ASCII representation which is used in zone files. In caches or in transit against an identical, but compressed form will be used. RR types are there expressed by numbers between 1 and 255. The same applies to class and TTL.
ASCII format:
The domain name of the object to which the resource record belongs (optional) time to live ( in seconds). Validity of Resource Records ( optional) protocol group to which the resource record belongs (optional) describes the type of resource records (resource data) data describing the resource record in detail (for example, an IP address for an A RR, or a host name for an NS RR) length of the following data
In some types more fields that are filed directly before
The permissible classes
In practice, almost invariably used IN. The other classes have only historical significance. From BIND servers is occasionally used CH to publish the version number of a name server.
- IN Internet
- CH Chaosnet ( rarely used)
- HS Hesiod ( rarely used)
- CS CSNET (no longer used )
The main RR types
- A IPv4 address of a host
- AAAA IPv6 address of a host
- AFSDB Resource Record for Cell Database server of the Andrew File System
- A6 resource record of the proceedings A6 to partially address resolution under IPv6, now outdated
- CERT resource record for saving certificates (see RFC 4398 )
- CNAME Canonical name for a host ( the domain with this RR is an alias )
- CNAME DNAME similar, but for entire domains, see RFC 2672
- DNSKEY contains a name associated public key - replaced with DNSSEC as of 2004 from the type KEY.
- DS - is the concatenation of DNSSEC signed zones
- GPOS Geographical position, outdated
- HINFO host information ( processor type and operating system )
- ISDN ISDN number is seldom used
- LOC Location
- KEY contains a name associated public key - is no longer used by DNSSEC since 2004
- MB mailbox domain name ( Experimental)
- MD mail destination ( no longer in use - today is used MX )
- MF mail forwarder ( no longer in use - today is used MX )
- MG mail group member ( Experimental)
- MINFO mailbox or mail list information
- MR Mail rename domain name ( Experimental)
- MX Mail Exchange - responsible for this domain mail server
- NAPTR Naming Authority Pointer - Expansion of the A resource record
- NSAP Network Service Access Point
- NSEC (next secure) concatenated DNS records in DNSSEC signed zones - dissolved 2004 Type NXT from
- NSEC3 (next secure hashed ) alternative to NSEC RR without zone enumeration problem (since 2008)
- Null null resource record ( Experimental)
- NS hostname of authoritative name server
- NXT outdated - was replaced by the virtually identical NSEC resource record
- OPT pseudo -RR, marked an EDNS packet
- PTR domain name pointer (for the reverse mapping to assign names to IP addresses)
- RP managers ( responsible ) person
- RRSIG contains a digital signature (used since 2004 DNSSEC ( = DNS Security) and replaced SIG)
- SIG includes a digital signature ( dated, was until 2004 DNSSEC ( = DNS Security ) is used )
- SOA Start of Authority
- SPF Sender Policy Framework
- SRV service offered (service)
- SSHFP SSH fingerprint, to publish the fingerprints of SSH keys, see RFC 4255
- TXT freely definable text is used, inter alia, for Sender Policy Framework (SPF ). Also commonly used for Google Site Verification
- WKS Well known service description
- X25 X.25 address is used only rarely