Ubuntu DNS resolver issue /etc/resolv.conf keeps getting over written by 127.0.0.53

Ubuntu DNS resolver issue is observed on ubuntu 18.04 onwards that /etc/resolv.conf keeps changing or over written even if the server is not rebooted nor the network service has been restarted.

Install resolvconf to resolve ubuntu dns resolver issue

sudo apt-get install resolvconf

Now lets go to below file and add our dns server

vi /etc/resolvconf/resolv.conf.d/head

# 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 192.168.2.2

Once our required dns servers are added to the head file, we need to restart the resolvconf service.

sudo systemctl restart resolvconf

sudo systemctl status resolvconf
● resolvconf.service - Nameserver information manager
   Loaded: loaded (/lib/systemd/system/resolvconf.service; enabled; vendor prese
   Active: active (exited) since Tue 2021-12-14 08:34:38 IST; 16s ago
     Docs: man:resolvconf(8)
  Process: 14624 ExecStop=/sbin/resolvconf --disable-updates (code=exited, statu
  Process: 14645 ExecStart=/sbin/resolvconf --enable-updates (code=exited, statu
  Process: 14642 ExecStartPre=/bin/touch /run/resolvconf/postponed-update (code=
  Process: 14634 ExecStartPre=/bin/mkdir -p /run/resolvconf/interface (code=exit
 Main PID: 14645 (code=exited, status=0/SUCCESS)

Dec 14 08:34:38 makeuseoflinux.com systemd[1]: Starting Nameserver information m
Dec 14 08:34:38 makeuseoflinux.com systemd[1]: Started Nameserver information

We can now see the new dns entry inside /etc/resolv.conf

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 192.168.2.2

We can also check the dns status using below command

systemd-resolve --status

 systemd-resolve --status
Global
         DNS Servers: 192.168.2.2
          DNSSEC NTA: 10.in-addr.arpa
                      16.172.in-addr.arpa
                      168.192.in-addr.arpa
                      17.172.in-addr.arpa
                      18.172.in-addr.arpa
                      19.172.in-addr.arpa
                      20.172.in-addr.arpa
                      21.172.in-addr.arpa
                      22.172.in-addr.arpa
                      23.172.in-addr.arpa

Solution

We have resolved ubuntu dns resolver issue by installing resolvconf package using apt-get and then added our required dns server in /etc/resolvconf/resolv.conf.d/head