Before you begin open a terminal with root user privileges.

There are 3 files that need to be edited.

First, edit the /etc/hosts file

nano /etc/hosts

Create a new line to show

127.0.0.1 <myhostname>.<myworkgroup/domain> <myhostname>

Press ctrl+o, then Enter to save. ctrl+x to quit

Edit the Hostname file

nano /etc/hostname

Optionally you could use the output redirect operator

echo "<myhostname>" > /etc/hostname

Edit the interfaces file

nano /etc/network/interfaces

If you’re using DHCP you can use the following

auto eth0
   allow-hotplug eth0
   iface eth0 inet dhcp

Or more likely if you would like to statically configure your IP address

auto eth0
iface eth0 inet static
   address 192.0.2.7/24
   gateway 192.0.2.254

If you prefer netmask in dot-decimal notation to CIDR notation you can use

auto eth0
iface eth0 inet static
   address 192.0.2.7
   netmask 255.255.255.0
   gateway 192.0.2.254

Update your system

apt update && apt upgrade -y

Edit your DNS settings. DNS settings can either be obtained via DHCP or by configuring it manually through the /etc/resolv.conf file

nano /etc/resolv.conf

Then add your 3 allowed name servers in order of fail-over

nameserver 1.1.1.1
nameserver 1.0.0.1
nameserver 208.67.222.222

You could be using your Pi-Hole or your forward proxy DNSMASQ for your first name server.

Reboot

reboot