How to solve the DNS problem in Ubuntu 18.04?

222 Asked by DanielCameron in Devops , Asked on Nov 29, 2023

I am a system administrator and work under Ubuntu 18.04 I have recently received a report from a wide range of users that they are unable to access certain network issues. After checking I found out that there was an issue related to DNS. How can I resolve the issue in Ubuntu 18.04?

Answered by Unnati gautam

In order to resolve the issue of DNS in Ubuntu 18.04 docker follow several steps:-

Check DNS configuration by using the command:-

  “cat /etc/resolv. Conf”

Under this, you have to ensure that there are valid DNS servers listed. If there is not, you can easily add it manually by using:-

  “sudo nano /etc/resolv.conf”

Flush DNS Cache by using the commands:-

  “Sudo system- resolve – flush- catches”

This above command will clear the DNS Cache files.

Checking DBLNS resolution by using:-

  “dig example.com” or “nslookup example.com”

Checking the Connectivity of the network by using:-

  “ ping www.googke.com”

Thus above command will check if the system can communicate with the external servers or not.

Restart Networking Services by using:-

Sudo systemct1 re-start networking” 

Checking Firewall settings by using:-

“sudo ufw status”

If the firewall is not active then, restart the firewall by using: the-

  “sudo ufw reload”

Follow the DevOps engineer course online to get more knowledge about Ubuntu 18.04.

How to solve the DNS problem in Ubuntu 18.04?

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