CLI for Managing Network Connections
The Network Manager Command Line Interface (nmcli) is the default tool installed on Ubuntu for managing the computer’s network connection from the command line.
An example situation that provides context for what we wish to achieve with nmcli is the following:
The robot’s computer is connected via the Ethernet port to your router at home.
Your personal laptop is connected to the WiFi network of your home router.
From your personal laptop you are logged-in to the robot’s computer via
ssh.You wish to connect the robot’s computer to the hotspot of your smartphone.
Once the robot’s computer is connected to the hotspot of your smartphone, then you can connect your personal laptop to the smartphone hotspot, and then you can run the robot from any location where you have the robot and your personal laptop connected to the hotspot of your smartphone.
Available devices and status
A good starting point is to always list the available networking devices and their status:
nmcli device status
Display available WiFi networks
Note
If any of the following commands do not work as expected, then try again with sudo
Note
In the following commands device can be replaced by dev if you want to save typing a few characters, the functionality is identical.
The simplest command to display available WiFi networks:
nmcli device wifi
If a network you are expecting is not visible, then you can force a rescan of the available wifi networks:
nmcli device wifi rescan
To display additional information about the scanned networks:
nmcli --fields ALL device wifi
Connecting to a new WiFi network
Use the network SSID listed using the command above, i.e., the network name, to connect to that WiFi network:
sudo nmcli device wifi connect <network-ssid> password "<network-password>"
where <network-ssid> and <network-password> are replaced accordingly. You can also leave off the password part of the command and you will be prompted to provide the password.
Note
If you are connected to the computer via ssh (or similar), then when you give the command to connect to a different (WiFi) network, your ssh connection will break.
Working with saved connections
Note
In the following commands connection can be replaced by con if you want to save typing a few characters, the functionality is identical.
Show saved connections:
nmcli connection show
Disconnect from a current connection:
nmcli connection down <network-ssid>
Connect to, or change the connection to, a saved network:
nmcli connection up <network-ssid>.
For these previous two commands, <network-ssid> should replaced by the SSID of the network, i.e., the network name.
