Gfilui

I'm looking for the correct way of configuring the network with static IP on Ubuntu Desktop 18.04, but from the command line and not the GUI.

Thank you

I think this is as close to the "correct way" as you can get.

First you must find out what your interface name is. To do that just run ip address from the Terminal. On my machine it is eno1 which can be found on the first line:

me@pc:~$ ip address
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
 link/ether 90:b1:1c:aa:bb:cc brd ff:ff:ff:ff:ff:ff
 inet 10.1.2.16/24 brd 10.1.2.255 scope global eno1
 valid_lft forever preferred_lft forever
 inet6 fe80::5cd1:3ee8:c461:6f12/64 scope link noprefixroute 
 valid_lft forever preferred_lft forever

Then you just need to edit the file /etc/netplan/01-network-manager-all.yaml and make it look like this for a static IP address assignment:

# Let NetworkManager manage all devices on this system
network:
 version: 2
 renderer: NetworkManager
 ethernets:
 eno1:
 renderer: networkd
 match:
 name: eno1
 addresses: [10.1.2.16/24]
 gateway4: 10.1.2.1
 nameservers:
 search: [example.com]
 addresses: [10.1.2.10]

This tells netplan to use networkd on the interface eno1 instead of NetworkManager.