Records

A (IPv4)

An “A” record, which stands for “address” is the most basic type of syntax used in DNS records, indicating the actual IP address of the domain. Regular DNS addresses are mapped for 32-bit IPv4 addresses.

AAAA (IPv6)

A “AAAA” (“quad A”) record is also an “address” record that indicates the actual IP address of the domain. It allows for mapping 128-bit IPv6 addresses.

CNAME

“CNAME” stands for “canonical name” and serves to make one domain an alias of another domain. The CNAME record is often used to associate new subdomains with the DNS records of an existing domain.

HINFO (Host Info)

“HINFO” stands for “Host Information Record,” and identifies the hardware and operating system of a host.

MX (Mail Exchange)

“MX” stands for “Mail Exchange” and contains a list of mail exchange servers that are to be used for the domain.

TXT (Text)

A “TXT” or Text record lets an administrator insert any text they would like into the DNS record, and it is often used for denoting facts about the domain.

RP (Responsible Person)

“RP” stands for “Responsible Person,” and the RP record identifies the contact information of the person (or group) responsible for a host or zone.

SRV (Service Locator)

A Service (SRV) record provides information (the location, i.e. hostname and port number) about available network services (for example, SIP and XMPP) based on a specific protocol and domain.

NAPTR (Naming Authority Pointer)

“NAPTR” stands for “Naming Authority Pointer.” The NAPTR record is most commonly used for applications in Internet telephony, for example, in the mapping of servers and user addresses in the Session Initiation Protocol (SIP). The combination of NAPTR records with Service Records (SRV) allows the chaining of multiple records to form complex rewrite rules which produce new domain labels or uniform resource identifiers (URIs).

NS (Name Server)

A Name Server (NS) record provides authoritative server information for a (sub) domain. Note: When you create or transfer a domain to UltraDNS, you will see two NS records created automatically: udns1.ultradns.net and udns2.ultradns.net. You cannot delete these system generated records. Unless you have a subdomain (for example, sterling.example.biz as a subdomain of example.biz), you should not add additional NS records without first consulting UltraDNS Support.

PTR (Pointer)

A Pointer (PTR) record provides address-to-name mapping (reverse mapping) in a reverse domain and consists of three fields: In-Addr, Points To, and TTL.

Note: You can automatically create PTR records when you create A records by selecting My Profile at the top right of the browswer window, opening System Preferences, and selecting Enabled in the Automatically create PTR records list.

SPF (Sender Policy Framework)

“SPF” stands for “Sender Policy Framework” and the SPR record is a type of TXT record that identifies which mail servers are permitted to send email on behalf of your domain. The purpose of an SPF record is to detect and prevent spammers from sending messages with forged From addresses on your domain.

CAA (Certification Authority Authorization)

“CAA” stands for “Certification Authority Authorization” and its purpose is to allow domain owners to declare which certificate authorities are allowed to issue a certificate for a domain. This record also provides a means for indicating notification rules in case someone requests a certificate from certificate authority that is not authorized.

TLSA (TLS Association)

Transport Layer Security Authentication (TLSA) provides communication security across the internet, by using channel encryption. The TLSA record is used to associate a TLS server certificate or public key with the domain name where the record is found, thereby forming a “TLSA certificate association.”

Apex Alias

An “Apex Alias” record basically prevents your users from having to enter the “www” at the beginning of a URL. Apex Alias allows you to replace an A record with a CNAME record that resolves to another host name. The Apex Alias functionality supports both IPv4 and IPv6 resolution, returning A and AAAA records as appropriate.

SSH Fingerprint

The DNS Secure Shell Fingerprint (SSHFP) record provides a way to verify Secure Shell (SSH) host keys using Domain Name System Security (DNSSEC). The SSHFP record is used to provide out-of-band verification, which looks up the SSHP fingerprint of the server public key in DNS, and then uses DNSSEC to verify the lookup.

Web Forwarding

A Web Forwarding record is used to redirect queries from a domain to another site. With web forwarding, you can register misspellings, alternate extensions (e.g., .biz, .net, etc.) and / or abbreviations, and then forward them to your primary website.