Unbound is an Open source DNS caching and recursive resolver. You can find more about unbound at
https://nlnetlabs.nl/projects/unbound/about/
To install unbound on Ubuntu/Debian, run
apt install unbound
To start unbound
systemctl start unbound
Set unbound to start on boot
systemctl enable unbound
To configure your server to use local name servers provided by unbound, edit file
vi /etc/resolv.conf
Add
nameserver 127.0.0.1
See dns