In a dns zone what type of record holds the name-to-address mapping for ipv4 addresses

This list of DNS record types is an overview of resource records (RRs) permissible in zone files of the Domain Name System (DNS). It also contains pseudo-RRs.

Resource records[edit]

TypeType id. (decimal)Defining RFCDescriptionFunctionA1RFC 1035[1]Address recordReturns a 32-bit IPv4 address, most commonly used to map hostnames to an IP address of the host, but it is also used for DNSBLs, storing subnet masks in RFC 1101, etc.AAAA28RFC 3596[2]IPv6 address recordReturns a 128-bit IPv6 address, most commonly used to map hostnames to an IP address of the host.AFSDB18RFC 1183AFS database recordLocation of database servers of an AFS cell. This record is commonly used by AFS clients to contact AFS cells outside their local domain. A subtype of this record is used by the obsolete DCE/DFS file system.APL42RFC 3123Address Prefix ListSpecify lists of address ranges, e.g. in CIDR format, for various address families. Experimental.CAA257RFC 6844Certification Authority AuthorizationDNS Certification Authority Authorization, constraining acceptable CAs for a host/domainCDNSKEY60RFC 7344Child copy of DNSKEY record, for transfer to parentCDS59RFC 7344Child DSChild copy of DS record, for transfer to parentCERT37RFC 4398Certificate recordStores PKIX, SPKI, PGP, etc.CNAME5RFC 1035[1]Canonical name recordAlias of one name to another: the DNS lookup will continue by retrying the lookup with the new name.CSYNC62RFC 7477Child-to-Parent SynchronizationSpecify a synchronization mechanism between a child and a parent DNS zone. Typical example is declaring the same NS records in the parent and the child zoneDHCID49RFC 4701DHCP identifierUsed in conjunction with the FQDN option to DHCPDLV32769RFC 4431DNSSEC Lookaside Validation recordFor publishing DNSSEC trust anchors outside of the DNS delegation chain. Uses the same format as the DS record. RFC 5074 describes a way of using these records.DNAME39RFC 6672Delegation name recordAlias for a name and all its subnames, unlike CNAME, which is an alias for only the exact name. Like a CNAME record, the DNS lookup will continue by retrying the lookup with the new name.DNSKEY48RFC 4034DNS Key recordThe key record used in DNSSEC. Uses the same format as the KEY record.DS43RFC 4034Delegation signerThe record used to identify the DNSSEC signing key of a delegated zoneEUI48108RFC 7043MAC address (EUI-48)A 48-bit IEEE Extended Unique Identifier.EUI64109RFC 7043MAC address (EUI-64)A 64-bit IEEE Extended Unique Identifier.HINFO13RFC 8482Host InformationProviding Minimal-Sized Responses to DNS Queries That Have QTYPE=ANYHIP55RFC 8005Host Identity ProtocolMethod of separating the end-point identifier and locator roles of IP addresses.HTTPS65IETF DraftHTTPS BindingRR that improves performance for clients that need to resolve many resources to access a domain. More info in this IETF Draft by DNSOP Working group and Akamai technologies.IPSECKEY45RFC 4025IPsec KeyKey record that can be used with IPsecKEY25RFC 2535[3] and RFC 2930[4]Key recordUsed only for SIG(0) (RFC 2931) and TKEY (RFC 2930).[5] RFC 3445 eliminated their use for application keys and limited their use to DNSSEC.[6] RFC 3755 designates DNSKEY as the replacement within DNSSEC.[7] RFC 4025 designates IPSECKEY as the replacement for use with IPsec.[8]KX36RFC 2230Key Exchanger recordUsed with some cryptographic systems (not including DNSSEC) to identify a key management agent for the associated domain-name. Note that this has nothing to do with DNS Security. It is Informational status, rather than being on the IETF standards-track. It has always had limited deployment, but is still in use.LOC29RFC 1876Location recordSpecifies a geographical location associated with a domain nameMX15RFC 1035[1] and RFC 7505Mail exchange recordList of mail exchange servers that accept email for a domainNAPTR35RFC 3403Naming Authority PointerAllows regular-expression-based rewriting of domain names which can then be used as URIs, further domain names to lookups, etc.NS2RFC 1035[1]Name server recordDelegates a DNS zone to use the given authoritative name serversNSEC47RFC 4034Next Secure recordPart of DNSSEC—used to prove a name does not exist. Uses the same format as the (obsolete) NXT record.NSEC350RFC 5155Next Secure record version 3An extension to DNSSEC that allows proof of nonexistence for a name without permitting zonewalkingNSEC3PARAM51RFC 5155NSEC3 parametersParameter record for use with NSEC3OPENPGPKEY61RFC 7929OpenPGP public key recordA DNS-based Authentication of Named Entities (DANE) method for publishing and locating OpenPGP public keys in DNS for a specific email address using an OPENPGPKEY DNS resource record.PTR12RFC 1035[1]PTR Resource Record [de]Pointer to a canonical name. Unlike a CNAME, DNS processing stops and just the name is returned. The most common use is for implementing reverse DNS lookups, but other uses include such things as DNS-SD.RRSIG46RFC 4034DNSSEC signatureSignature for a DNSSEC-secured record set. Uses the same format as the SIG record.RP17RFC 1183Responsible PersonInformation about the responsible person(s) for the domain. Usually an email address with the @ replaced by a .SIG24RFC 2535SignatureSignature record used in SIG(0) (RFC 2931) and TKEY (RFC 2930).[7] RFC 3755 designated RRSIG as the replacement for SIG for use within DNSSEC.[7]SMIMEA53RFC 8162[9]S/MIME cert association[10]Associates an S/MIME certificate with a domain name for sender authentication.SOA6RFC 1035[1] and RFC 2308[11]Start of [a zone of] authority recordSpecifies authoritative information about a DNS zone, including the primary name server, the email of the domain administrator, the domain serial number, and several timers relating to refreshing the zone.SRV33RFC 2782Service locatorGeneralized service location record, used for newer protocols instead of creating protocol-specific records such as MX.SSHFP44RFC 4255SSH Public Key FingerprintResource record for publishing SSH public host key fingerprints in the DNS, in order to aid in verifying the authenticity of the host. RFC 6594 defines ECC SSH keys and SHA-256 hashes. See the IANA SSHFP RR parameters registry for details.SVCB64IETF DraftService BindingRR that improves performance for clients that need to resolve many resources to access a domain. More info in this IETF Draft by DNSOP Working group and Akamai technologies.TA32768—DNSSEC Trust AuthoritiesPart of a deployment proposal for DNSSEC without a signed DNS root. See the IANA database and Weiler Spec for details. Uses the same format as the DS record.TKEY249RFC 2930Transaction Key recordA method of providing keying material to be used with TSIG that is encrypted under the public key in an accompanying KEY RR.[12]TLSA52RFC 6698TLSA certificate associationA record for DANE. RFC 6698 defines "The TLSA DNS resource record is used to associate a TLS server certificate or public key with the domain name where the record is found, thus forming a 'TLSA certificate association'".TSIG250RFC 2845Transaction SignatureCan be used to authenticate dynamic updates as coming from an approved client, or to authenticate responses as coming from an approved recursive name server[13] similar to DNSSEC.TXT16RFC 1035[1]Text recordOriginally for arbitrary human-readable text in a DNS record. Since the early 1990s, however, this record more often carries machine-readable data, such as specified by RFC 1464, opportunistic encryption, Sender Policy Framework, DKIM, DMARC, DNS-SD, etc.URI256RFC 7553Uniform Resource IdentifierCan be used for publishing mappings from hostnames to URIs.ZONEMD63RFC 8976Message Digests for DNS ZonesProvides a cryptographic message digest over DNS zone data at rest.

Other types and pseudo-RRs[edit]

Other types of records simply provide some types of information (for example, an HINFO record gives a description of the type of computer/OS a host uses), or others return data used in experimental features. The "type" field is also used in the protocol for various operations.

TypeType id.Defining RFCDescriptionFunction*255RFC 1035[1]All cached recordsReturns all records of all types known to the name server. If the name server does not have any information on the name, the request will be forwarded on. The records returned may not be complete. For example, if there is both an A and an MX for a name, but the name server has only the A record cached, only the A record will be returned. Usually referred to as ANY (e.g., in dig, Windows nslookup, and Wireshark). In 2019, RFC8482 [14] standards-track publication led many DNS providers, including Cloudflare,[15] to provide only minimal responses to "ANY" queries, instead of enumerating records.AXFR252RFC 1035[1]Authoritative Zone TransferTransfer entire zone file from the primary name server to secondary name servers.IXFR251RFC 1996Incremental Zone TransferRequests a zone transfer of the given zone but only differences from a previous serial number. This request may be ignored and a full (AXFR) sent in response if the authoritative server is unable to fulfill the request due to configuration or lack of required deltas.OPT41RFC 6891OptionThis is a pseudo-record type needed to support EDNS.

[1] Obsolete record types[edit]

Progress has rendered some of the originally defined record-types obsolete. Of the records listed at IANA, some have limited use, for various reasons. Some are marked obsolete in the list, some are for very obscure services, some are for older versions of services, and some have special notes saying they are "not right".

Which zone maps name to IP address in DNS?

What is an A records in a DNS zone?

What type of A record should you use to map a domain name to an IP address?

What type of DNS record will map a name to an existing A record?