systemd

systemd-resolved (dns stub)

to check if port 53 (dns) is in use

sudo lsof -i :53

systemd-resolved config file

/etc/systemd/resolved.conf

force link to config file instead of using default

sudo ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf

disable dns stub

DNSStubListener=no

configure dns server to use

DNS=1.1.1.1

disabling systemd-resolved completely

sudo systemctl disable systemd-resolved.service 
sudo systemctl stop systemd-resolved.service