Ubuntu 22.04 changed the way nameservers are defined. Now it uses “netplan”. It’s possible to update the nameservers with netplan by editing the YAML configuration file. But if you’re old-school or just don’t like netplan, here’s how to update the nameservers in your /etc/resolv.conf file the correct way…
Start by installing package “resolvconf”: apt-get install resolvconf
Next, edit file /etc/resolvconf/resolv.conf.d/head. Update the nameservers there. Then run these two commands:
resolvconf --enable-updatesresolvconf -u
After that, you can look at /etc/resolv.conf to verify that your nameservers were correctly propagated. And that’s it!