Set a static IP in Debian
Debian's non-graphical install does not give you the option to set a static IP, here's a quick guide to doing it manually on the command line.
Login to Debian as root or as a user with sudo privileges (be sure to append sudo before every command). First, save a copy of the default network config as a back up:
cp /etc/network/interfaces /backups/
Now edit the file:
nano /etc/network/interfaces
Look for these lines towards the end of the file:
# The primary network interface
allow-hotplug enp0s25
iface enp0s25 inet dhcp
Edit to the following:
# The primary network interface
auto enp0s25
iface enp0s25 inet static
address 192.168.1.250
netmask 255.255.255.0
gateway 192.168.1.254
dns-nameservers 1.1.1.1 8.8.8.8
Save and close the file, then restart the network interface:
systemctl restart ifup@enp0s25
Then restart the networking service and check it’s status:
systemctl restart networking.service
systemctl status networking.service
If there’s no errors, the output should look something like this:
● networking.service - Raise network interfaces
Loaded: loaded (/lib/systemd/system/networking.service; enabled; vendor preset: enabled)
Active: active (exited) since Wed 2022-10-05 16:44:08 EDT; 2h 5min ago
Docs: man:interfaces(5)
Main PID: 490 (code=exited, status=0/SUCCESS)
Tasks: 0 (limit: 1112)
Memory: 0B
CPU: 0
CGroup: /system.slice/networking.service
If you get an error, try running systemctl restart NetworkManager.service or systemctl restart network-manager instead. If you still get an error, you may need to edit (or if it doesn’t exist, create) the file at /etc/resolv.conf. Add your DNS resolvers like this:
nameserver 1.1.1.1
nameserver 1.0.0.1
Save and close the file, then try checking restarting and checking the status again. You may need to reboot for the changes to take effect.
Once the networking.service is up and running, also check your IP address with the following command:
ip -c addr show enp0s25
Output should look similar to this:
2: enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether 70:5a:b6:ac:52:d6 brd ff:ff:ff:ff:ff:ff
inet 192.168.0.250/24 brd 192.168.0.255 scope global enp0s25
valid_lft forever preferred_lft forever
inet6 fe80::725a:b6ff:feac:52d6/64 scope link
valid_lft forever preferred_lft forever
If the static IP Address you configured appears in the output, you’re done!