Debian - Static IP addressing
Edit this file with your preferred editor.
nano /etc/network/interfaces
I use nano because I rarely have any issues with it.
Amend the file to look something like this. Most of the time you will only need to make changes below the comment line # The primary network interface
# The primary network interface
#allow-hotplug ens192
#iface ens192 inet dhcp
auto ens192
iface ens192 inet static
address 192.168.100.100
netmask 255.255.255.0
gateway 192.168.100.1
dns-domain <your-domain-name>
dns-nameservers <preferred-dns-server(s)>
Restart networking
systemctl restart networking
Check that the IP address is set correctly
ip a