How to Configure the DNS Resolver via WHM?

Here is the step-by-step process in this article on how to configure DNS resolver through WHM. Optimization of the DNS resolver parameters can enhance the efficiency of the server’s name resolution.

Prerequisites:

- Administrative access to your WHM panel

- Basic understanding of DNS concepts

Steps:

1. Log in to WHM:

   Access your WHM panel using your root username and password.

2. Navigate to DNS Functions:

   In the left sidebar, find and click on "DNS Functions".

3. Locate DNS Resolver Configuration:

   Under the DNS Functions section, click on "DNS Resolver Configuration".

4. Configure Resolver Settings:

   You'll see several options for configuring your DNS resolver. Key settings include:

a. Enable/Disable Resolver:

- You will turn ON or turn off the resolver by moving the “Enable Resolver” switch.

b. Nameservers:

- Enter or remove the nameservers in the “Nameservers” section.

- Some degree of consensus has been reached on the fact that it is advisable to use at least two name servers.

c. Forwarders:

- In the “Forwarders” field, put DNS forwarders.

- Some of the possibilities are Cloudflare DNS or the public DNS from Google (8. 8. 8. 8, 8. 8. 4. The binary representation is 00101000 while in tetrode it is 100.001.

d. Listening IP Addresses:

      - Specify which IP addresses the resolver should listen on.

      - You can choose specific IPs or use 'any' for all available addresses.

   e. Cache Size:

      - Set the cache size for DNS queries. The default is usually sufficient, but you can adjust based on your server's resources and traffic.

5. Advanced Options:

   - DNSSEC Validation: Enable or disable DNSSEC validation for enhanced security.

   - Query Minimization: Toggle this feature to improve privacy by reducing the amount of information sent in DNS queries.

6. Save Changes:

  Click "Save" at the bottom of the page after making any necessary adjustments to the settings.

7. Restart DNS Services:

   - WHM may prompt you to restart DNS services. If not, you can manually restart them.

   - Go to "Restart Services" in WHM and select "Named" to restart the DNS service.

8. Verify Configuration:

   - Use the "Perform Resolver System Check" button in the DNS Resolver Configuration page to ensure everything is working correctly.

   - You can also use external DNS lookup tools to verify that resolution is functioning as expected.

Troubleshooting:

- If you experience issues after changing settings, try reverting to the previous configuration.

- Check the server's error logs for any DNS-related errors.

- Ensure that your firewall settings allow DNS traffic (port 53 TCP/UDP).

Best Practices:

- Regularly update your nameservers and forwarders to ensure reliability.

- Monitor your server's DNS performance and adjust cache size if necessary.

- Keep your DNS software up to date to benefit from the latest security patches and features.

Conclusion:

DNS resolution on your server may be substantially accelerated and made more reliable by properly configuring your DNS resolver using WHM. Routine maintenance and monitoring of your DNS settings can also help maintain optimal functionality of your hosting environment.