How to set permanent DNS nameservers on Ubuntu 21.04

To Set Permanent DNS Nameservers on Ubuntu 21.04

Introduction

DNS stands for Domain Name System server, which is responsible for translating a domain name into an IP address. Using custom DNS servers on Linux can improve performance and security.

Installation Procedure:

Step 1: Check the OS version by using the following command

root@linuxhelp:~# lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 21.04
Release:	21.04
Codename:	hirsute

Step 2: Install the resolvconf package by using the following command

root@linuxhelp:~# apt install resolvconf
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed:
  resolvconf
0 upgraded, 1 newly installed, 0 to remove and 263 not upgraded.
Need to get 54.7 kB of archives.
After this operation, 203 kB of additional disk space will be used.
Get:1 http://in.archive.ubuntu.com/ubuntu hirsute/universe amd64 resolvconf all 1.84ubuntu1 [54.7 kB]
Fetched 54.7 kB in 6s (9,526 B/s)     
Preconfiguring packages ...
Selecting previously unselected package resolvconf.
(Reading database ... 151399 files and directories currently installed.)
Preparing to unpack .../resolvconf_1.84ubuntu1_all.deb ...
Unpacking resolvconf (1.84ubuntu1) ...
Setting up resolvconf (1.84ubuntu1) ...
Created symlink /etc/systemd/system/sysinit.target.wants/resolvconf.service → /lib/systemd/system/resolvconf.service.
Created symlink /etc/systemd/system/systemd-resolved.service.wants/resolvconf-pull-resolved.path → /lib/systemd/system/resolvconf-pull-resolved.path.
Created symlink /etc/systemd/system/systemd-resolved.service.wants/resolvconf-pull-resolved.service → /lib/systemd/system/resolvconf-pull-resolved.service.
Processing triggers for man-db (2.9.4-2) ...
Processing triggers for resolvconf (1.84ubuntu1) ...

Step 3: Start the resolvconf service by using the following command

root@linuxhelp:~# systemctl start resolvconf.service

Step 4: Enable the resolvconf service by using the following command

root@linuxhelp:~# systemctl enable resolvconf.service
Synchronizing state of resolvconf.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable resolvconf

Step 5: Check the status of the resolvconf service

root@linuxhelp:~# systemctl status resolvconf.service
● resolvconf.service - Nameserver information manager
     Loaded: loaded (/lib/systemd/system/resolvconf.service; enabled; vendor preset: enabled)
     Active: active (exited) since Sat 2021-10-30 22:53:19 IST; 1min 55s ago
       Docs: man:resolvconf(8)
   Main PID: 6298 (code=exited, status=0/SUCCESS)
      Tasks: 0 (limit: 2257)
     Memory: 0B
     CGroup: /system.slice/resolvconf.service

Oct 30 22:53:19 linuxhelp systemd[1]: Started Nameserver information manager.
Oct 30 22:53:19 linuxhelp resolvconf[6303]: /etc/resolvconf/update.d/libc: Warning: /etc/resolv.conf is not>

Step 6: Enter the nameservers in the resolv.conf.d by using the following command

root@linuxhelp:~# nano /etc/resolvconf/resolv.conf.d/head 

Step 7: Update the resolvconf by using the following command

root@linuxhelp:~# resolvconf -u

Step 8: Check the nameserver entry reflected in resolv.conf

root@linuxhelp:~# nano /etc/resolv.conf 

By this How to set permanent DNS nameservers on Ubuntu 21.04 comes to end

FAQ
Q
What is Resolvconf?
A
It is file used in various operating systems to
configure the system's DNS resolver
Q
How to Find My DNS Server IP Address
A
We can find DNS Server IP Address by using following command "cat /etc/resolv.conf"
Q
What is meant by DNS?
A
DNS, or the domain name system, is the phonebook of the Domains.
Q
Where is the location of static DNS file ?
A
It is located in /etc/resolvconf/resolv.conf.d/
Q
Why DNS entry in resolv.conf disables ?
A
It is a dynamic file, resolv.conf , on every reboot it auto resets to its default settings.