nmcli

nmcli is a command-line interface for managing NetworkManager, a tool used to manage network connections on Linux-based systems. It provides a convenient way to configure network interfaces, Wi-Fi connections, VPNs, and other networking configurations directly from the command line.

Key Features and Subcommands

Here’s a breakdown of some common nmcli commands and their usage:

1. nmcli general

Used to display general system network settings and manage NetworkManager.

• Show general status of NetworkManager:

  nmcli general status

  This command shows the overall status of NetworkManager (e.g., whether it's running).

• Show the NetworkManager version:

  nmcli general version

• Enable/Disable NetworkManager:

  nmcli general enable
  nmcli general disable

2. nmcli device

Manages network devices and shows their status.

• Show all network devices:

  nmcli device status

  Displays the status of all network devices (e.g., Ethernet, Wi-Fi, etc.).

• Bring a device up or down:

  nmcli device connect eth0
  nmcli device disconnect eth0

• Show detailed information about a device:

  nmcli device show eth0

• Change device connection:

  nmcli device wifi connect SSID password "yourpassword"

3. nmcli connection

Used to manage network connections (Ethernet, Wi-Fi, VPN, etc.).

• Show all connections:

  nmcli connection show

• Show a specific connection:

  nmcli connection show <connection-name>

• Activate a connection:

  nmcli connection up <connection-name>

• Deactivate a connection:

  nmcli connection down <connection-name>

• Add a new Wi-Fi connection:

  nmcli connection add type wifi ifname wlan0 con-name mywifi autoconnect yes ssid MySSID

• Delete a connection:

  nmcli connection delete <connection-name>

• Edit a connection:

  nmcli connection modify <connection-name> ipv4.addresses 192.168.1.100/24

4. nmcli networking

Used to control the overall networking status.

• Enable or disable networking:

  nmcli networking off
  nmcli networking on

5. nmcli radio

Used to control the wireless radio (Wi-Fi) state.

• Enable Wi-Fi radio:

  nmcli radio wifi on

• Disable Wi-Fi radio:

  nmcli radio wifi off

• Enable/Disable Bluetooth radio:

  nmcli radio bluetooth on
  nmcli radio bluetooth off

6. nmcli vpn

Manages VPN connections.

• Show VPN connections:

  nmcli vpn show

• Add a VPN connection:

  nmcli connection add type vpn vpn-type openvpn con-name myvpn ifname -- vpn-service-type org.freedesktop.NetworkManager.openvpn

• Activate a VPN connection:

  nmcli connection up myvpn

7. nmcli monitor

Monitors network status in real-time.

• Monitor changes to connections:

  nmcli monitor

This command will keep the terminal open and monitor any network changes in real-time.

8. nmcli wifi

Manages Wi-Fi connections and networks.

• List available Wi-Fi networks:

  nmcli device wifi list

• Connect to a Wi-Fi network:

  nmcli device wifi connect SSID password "yourpassword"

• Disconnect from the current Wi-Fi network:

  nmcli device disconnect wlan0

Examples of nmcli Usage

1. Check the current connection status:

   nmcli connection show --active

2. Change the IP address of an interface:

   nmcli connection modify "Wired connection 1" ipv4.addresses 192.168.0.100/24

3. Create a new Ethernet connection:

   nmcli connection add type ethernet con-name "MyEthernet" ifname eth0 ipv4.addresses 192.168.0.101/24

4. Enable and disable Wi-Fi:

   nmcli radio wifi off
   nmcli radio wifi on

5. Activate or deactivate a connection:

   nmcli connection up "MyWifi"
   nmcli connection down "MyWifi"

Conclusion

nmcli is a powerful and flexible tool for managing network connections on Linux systems. Whether you're configuring an Ethernet connection, connecting to Wi-Fi, managing VPNs, or even controlling network device states, nmcli provides a comprehensive set of commands to handle all your network configuration needs from the command line.