1. bluehost knowledge base

DNS Records Introduction: A Beginners Guide

DNS (Domain Name System) entries can quickly be updated with some propagation time, which is the length of time needed to update records across the Internet. Here are some explanations below to help you understand DNS records' basics and how it usually works in real-world scenarios.



A Record

An A record (Address Record, also known as a host record, points to an IP address's domain name or subdomain.

For example:
yourdomain.com points to 12.345.678.90
mail.yourdomain.com to 12.345.678.90

Usually, the domain owners assign IP addresses to a specific function such as their domain, subdomain, email, etc., allowing them to connect it from a specific server.

CNAME

A CNAME (Canonical Name) record points the subdomain to another domain or another subdomain.

For example:

  1. www.example.com to example.com
  2. imap.example.com to mail.example.com
  3. docs.example.com to ghs.google.com.
    • The first record allows the domain (example.com) to resolve the same server with 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 to ghs.google.com with G Suite, where you can use Google's document management system. This type of record requires additional configuration with Google.

MX Entry

An MX Entry (Mail Exchanger) directs email to a particular mail server(s) that has a priority in which of them will be used if the other one fails to receive the email.

For example:

Email address:example@yourdomain.com
Hostname: mail
MX Record: mail.yourdomain.com
IP address: 12.345.678.90

All emails sent to example@yourdomain.com will be sent to the mail server of mail.yourdomain.com, pointing to the 12.345.678.90 IP address. For more information on managing MX records, please see DNS Management - How To Edit MX Records.

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.

For example:

  • 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). More information on SPF records can be found at http://www.openspf.net/
  • Another one is for DomainKeys, which is also used to verify that email came from a trusted source. More information on DomainKeys can be found at http://www.dkim.org/.

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.

For more information on TXT records, please see What a is TXT Record.

SRV record

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

For 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, but it allows 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 / Hostname - 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 - This is used by the server or computer 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.

For further assistance, you may contact our Chat Support or Phone Support via 888-401-4678. You may also refer to our Knowledge Base articles to help answer common questions and guide you through various setup, configuration, and troubleshooting steps.