What Are DNS Records? Understanding the Basics

DNS (Domain Name System) entries take a human-friendly name, such as store.example.com, and translate it to an IP address. The DNS can quickly be updated with some propagation time, which is the length of time needed to update records across the Internet. There are some DNS Entries you can create. The following DNS Entries can be created or modified from within the DNS Zone Editor. For help, see How to Modify Your DNS Records.

• A Record
• CNAME
• MX Entry
• TXT Record
• SRV Record
• AAAA Record
• DNS Glossary
• Additional Information

A Record

An A record (Address Record) points a domain or subdomain to an IP address. For example, you can use it for store.website.com or blog.website.com and point it to where you have your store. This is a common practice for people who use Amazon, eBay, Tumblr, etc.

For example, an A Record is used to point a logical domain name, such as "google.com," to the IP address of Google's hosting server, "74.125.224.147".

These records point traffic from example.com (indicated by @) and ftp.example.com to the IP address 66.147.224.236. They also point localhost.example.com to the server that the domain is hosted on. This allows the end-user to type in a human-readable domain while the computer can continue to work with numbers.

Examples of A records within the Bluehost DNS Record Interface.:

CNAME

A CNAME (Canonical Name) points one domain or subdomain to another domain name, allowing you to update one A Record each time you make a change, regardless of how many Host Records need to resolve to that IP address.

These records point to www.example.com to example.com, imap.example.com to mail.example.com, and docs.example.com to ghs.google.com. The first record allows the domain to resolve to the same server with or without the www subdomain. The second record allows you to use an alternative subdomain for email hosting and delivery. The third record allows you to use the docs.example.com subdomain with G Suite, where you can use Google's document management system. This type of record requires additional configuration with Google.

Examples of CNAME records within the Bluehost DNS Record Interface.

MX Entry

An MX Entry (Mail Exchanger) directs email to a particular mail server. Like a CNAME, MX Entries must point to a domain and never point directly to an IP address.

Examples of MX records within the Bluehost DNS Record Interface.

TXT Records

A TXT (Text) record was originally intended for human-readable text. These records are dynamic and can be used for several purposes. TXT records are commonly used for Google Verification.

The TXT Value is what the record 'points to,' but these records aren't used to direct any traffic. Instead, they're used to provide needed information to outside sources.

The First record is used for an SPF, Sender Policy Framework, records. Those records are used by many email systems to help identify if the email is coming from a trusted source, helping filter out spam or messages pretending to be from your domain (called spoofing).

The second record is used for DomainKeys, which is also used to verify that the email came from a trusted source. More information on DomainKeys can be found at http://www.dkim.org/.

Examples of TXT records within the Bluehost DNS Record Interface.

SRV record

An SRV (Service) record points one domain to another domain name using a specific destination port. In addition, SRV records allow specific services, such as VOIP or IM, to be directed to a separate location.

Example:

Enabling your domain to use Google's XMPP server is a good example to showcase. Google's help article states that the SRV record should be in this format:

_xmpp-server._tcp.gmail.com. IN SRV 5 0 5269 xmpp-server.l.google.com.

Under "Add DNS Record," you will need to enter the settings this way:

• Service: _xmpp-server
• Protocol: _tcp
• Host: chat (If you want to use the chat subdomain. Replace this with the subdomain that you want to use, or @ for the root domain.)
• TTL: 14400
• Type: SRV
• Priority: 5
• Weight: 0
• Port: 5269
• Points To: xmpp-server.l.google.com

AAAA Record

The AAAA record is similar to the A record, allowing you to point the domain to an Ipv6 address. More information on IPv6 can be found at http://ipv6.com/.

DNS Glossary

• Zone File - This is where all the DNS records are stored for a domain.
• Host Record - This is the domain or subdomain you wish to use. The @ symbol is used to indicate the root domain itself. In our example, the Host Record 'ftp' would be for the subdomain ftp.google.com and '@' would be google.com itself.
• Points to - This is the destination server that the domain or subdomain is sending the traffic to.
• TTL - The 'time to live' value indicates the amount of time the record is cached by a DNS Server, such as your Internet service provider. The default (and lowest accepted) value is 14400 seconds (4 hours). You do not normally need to modify this value.
• Action - This allows you to modify or remove existing records.
• Weight -  This is similar to priority, as it controls the order in which multiple records are used. Records are grouped with other records that have the same Priority value. As with MX Entries, lower numbers are used before higher numbers.
• Port - The server or computer uses this to process traffic to specific services, ensuring that all traffic comes through the door that it's expected.
• Target - This is the destination the record is sending traffic to.

Additional Information

Summary

DNS (Domain Name System) records are key to navigating the internet. They help translate easy-to-remember domain names into the numerical IP addresses that computers use, ensuring that web traffic flows smoothly. There are several types of DNS records, each serving a unique purpose: A Records connect domain names to their corresponding IP addresses. CNAME Records allow one domain to be known by more than one name, essentially aliasing it to another domain. MX Records are responsible for email routing, directing your emails to the correct mail server. TXT Records provide additional information, such as email authentication details, to support various services. SRV Records specify the location of servers for specific services, like VOIP (Voice Over Internet Protocol). AAAA Records point domains to IPv6 addresses, the next generation of IP addresses.

It's important to back up these records to maintain your online presence, especially during changes in your web hosting service.

Understanding DNS records is just the beginning. Next, you can explore how these records fit into the broader Domain Name System or learn how to configure them through the WHM (Web Host Manager) interface after purchasing a web hosting plan.