How to Set permanent DNS nameservers on Ubuntu with resolv.conf 

With the default resolv.conf file in ubuntu the nameserver is mentioned as following  "nameserver 127.0.0.53".

Resolv.conf file Ubuntu

The Original DNS servers behind this can be found with "resolvectl status" command.

resolvectl status

The problem with that , you fill face "Temporary name resolution failures" errors frequently. To Solve that we'll need to do the foloowing steps.

Solution:

Installing resolvconf package

Let’s install the resolvconf package. Enter the following code:

sudo apt update
sudo apt install resolvconf

To enable and start the resolvconf service, enter the following code:

sudo systemctl enable resolvconf.service
sudo systemctl start resolvconf.service
sudo systemctl status resolvconf.service

Resolvconf service status

Set DNS servers in resolv.conf using head file

Now we get to the meat of this article. Let’s open the head file:

sudo nano /etc/resolvconf/resolv.conf.d/head

Enter your nameservers below the comments (I’m using Google’s DNS servers).

nameserver 192.168.0.1
nameserver 8.8.8.8

We need to update resolv.conf to use the new nameservers. Enter the following code:

sudo resolvconf --enable-updates
sudo resolvconf -u

root@k8s-master:~# cat /etc/resolv.conf

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)

#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN

# 127.0.0.53 is the systemd-resolved stub resolver.

# run "systemd-resolve --status" to see details about the actual nameservers.

nameserver 192.168.0.1

nameserver 8.8.8.8

nameserver 127.0.0.53

options edns0 trust-ad

root@k8s-master:~#