DNS Record Types Explained

The Domain Name System (DNS) is the directory for the internet that helps organize and identify locations.  It's a guide that helps direct people to the desired location, like a home address.  DNS translates the human-identifiable domain names into physical IP addresses your computer can read.

DNS records are like road signs that help direct you to a physical address.  They are various strings of letters that make the commands for actions the server will follow.  Common DNS records are A, CNAME, MX, NS, TTL, TXT, and URL.  Below we will walk through the most common DNS records.

AAAA

Returns a 128-bit IPv6 address, most commonly used to map hostnames to an IP address of the host.

A Record

An A record (Address or host record) connects a domain to the IP address or computer hosting the domains website and/or services.

CNAME Record

A CNAME, Canonical Name, record connects aliases or other desired names to the true CNAME domain name.  For example, bare domains like example.com can be directed to www.example.com.

MX Record

MX, or Mail Exchange, records send a domain's email to the server the domain's user account is hosted on.

NS Record

The NS, or Nameserver, record decides which servers will send DNS information for a domain.  Typically, you establish primary and secondary name server records for your domain.

PTR

Returns only the name because DNS processing is stopped. Points to a canonical name.  Commonly used in reverse DNS lookups and DNS-SD.

SOA

The start of authority determines what information in the DNS zone will be used.  This includes information such as, primary name server, the domain serial number, email of the domain administrator, and setting a timer for refreshing the zone.

TTL Record

TTL or Time to Live, record sets how much time it will take for changes to go into effect.  Typically defined in seconds, many other name records also have a TTL value, including MX, CNAME, etc. For example, give something a 3600 value, and it will take one hour for the change to take effect.

Changes made to the TTL value will be constantly checked across the Internet based on the value.  These changes will be for subsequent updates and only checked at the interval period you have chosen in the TTL value.  For example,  a 3600 value tells servers to check your website every hour for new updates.

TXT

Machine-readable data that includes sender Policy Framework, DNS-SD, DMARC, DKIM, and opportunistic encryption.  This started originally as random human-readable text.

URL Record

A URL, or Uniform Resource Locator, is the web address of the website on the Internet.  This is information you type into your browser to direct it to a specific website, like, www.hostwinds.com.