Set a static IP in Debian

updated

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.

Table of Contents

  1. Setting a static IP
  2. References

Setting a static IP

Login to Debian as root or as a user with sudo privileges (in which case, 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 ~/interfaces.bk

Now edit the file:

nano /etc/network/interfaces

Look for these lines towards the end of the file:

# The primary network interface
allow-hotplug enp3s0
iface enp3s0 inet dhcp

Although I use the example enp3s0 in this post, your default network interface might be named differently, like enp0s2 or eth0, or something else entirely. If you use wireless instead of ethernet it will be something like wlan0.

See your default interface by using the command: ip -o -4 route show to default

Edit it to look like the following:

# The primary network interface
auto enp3s0
iface enp3s0 inet static
# server IP address
 address 192.168.0.125 
# /24 subnet
 netmask 255.255.255.0
# router IP address
 gateway 192.168.0.1
# dns
 dns-nameservers 1.1.1.1 8.8.8.8

Make sure to change the commented lines to your own server IP, router, DNS, and if necessary netmask (255.255.255.0 is equivalent to 192.168.0.0) — then save and close the file, then use this command to restart the network interface:

systemctl restart ifup@enp3s0

Then restart the networking service and check it’s status with these commands:

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; preset: enabled)
     Active: active (exited) since Sat 2025-01-18 14:19:00 EST; 2 weeks 3 days ago
       Docs: man:interfaces(5)
   Main PID: 812 (code=exited, status=0/SUCCESS)
        CPU: 26ms

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 restarting networking.service 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 enp3s0

Output should look similar to this:

2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 14:b3:1f:0a:81:37 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.125/24 brd 192.168.0.255 scope global dynamic enp3s0
       valid_lft 24218sec preferred_lft 24218sec
    inet6 fe80::16b3:1fff:fe0a:8137/64 scope link
       valid_lft forever preferred_lft forever

If the static IP address you configured (in my case 192.168.0.125) appears in the output, you’re done!

References