The way to configure a static IP in Ubuntu 18 is a bit different that the one in Ubuntu 16 and the previous versions. The file that needs to be modified is called 50-cloud-init.yaml and is located here: /etc/netplan. We will edit it.
sudo nano /etc/netplan/50-cloud-init.yaml
Originally, the file looks like this:
We need to add a couple of lines, but – very important – we should not change the indentation. I’ve struggled with some error messages when applying settings just because I’ve used TAB instead of SPACE, or because the indentation was off.
After modifications, the file should look like this:
We apply the new configuration using this command:
sudo netplan apply
NOTE: My netmask is 255.255.240.0, and that translates to 20 bits. If you have the more common netmask in your network, 255.255.255.0, then use 24 bits. Otherwise, use this table to find the number of bits required for you specific configuration: