How to Change DNS IP Address in RHEL: A Comprehensive Guide

This guide is designed to help you understand and adjust the DNS settings in RHEL (Red Hat Enterprise Linux) to ensure optimal network performance and reliability. Specifically, we will focus on how to modify DNS IP addresses through the file and handle cases where NetworkManager is enabled and interfering with DNS configuration.

Introduction to DNS in RHEL

Domain Name System (DNS) plays a crucial role in resolving domain names to IP addresses, enabling smoother communication over the internet. In RHEL, DNS configuration is primarily handled through the file, where DNS IP addresses are specified. Understanding and modifying these settings can enhance network performance and security.

Locating and Modifying DNS IP Addresses in RHEL

When you need to change the DNS IP addresses in RHEL, follow these steps:

Locate the file using the command:

sudo find / -name 

Once you have located the file, open it with a text editor:

sudo vi 

Modify or add the DNS IP addresses as needed, typically following the format:

nameserver 8.8.8.8nameserver 1.1.1.1nameserver 9.9.9.9

It's important to use reliable and authoritative DNS servers for security and performance reasons.

Handling NetworkManager Interference

NetworkManager, a powerful network management system in RHEL, can interfere with DNS configuration by overwriting changes made to the file. To prevent this, you can add a configuration directive to the NetworkManager settings.

Locate the file using the command:

sudo find / -name 

Open the file with a text editor:

sudo vi 

Add the following line to the [main] section of the file:

dnsnone

This directive tells NetworkManager not to manage DNS settings, which can prevent it from overwriting your custom DNS IP addresses.

Conclusion

By following the steps outlined in this guide, you can successfully modify DNS IP addresses in RHEL to suit your network needs. Whether you're enhancing performance, upgrading to a more robust DNS provider, or safeguarding against potential overwrites by NetworkManager, this article provides a clear and practical path to achieving your goals. Remember to always test DNS changes to ensure that your network functions as expected.