How can I disable my internet connection from terminal?

Question

The connect automatically option is allowed for my wired Wired connection 1. Disconnecting the connection works when I do it from the panel's Network > Disconnect menu. But when I do that with command:

nmcli con down id "Wired connection 1"

no sooner than it disconnects, the connection is back on.

How does Network > Disconnect work? Could we do the same with nmcli without disabling the automatic connection?

Note:

1. nmcli con down id "Wired connection 1" works as with automatic connection disabled (but again that's not an option),
2. I don't want to use sudo (wouldn't be good to implement in a script!).

Answer 1

The following command works for me like a charm if I want to disable any internet connection from terminal:

nmcli networking off

To enable it again:

nmcli networking on

Note: As commented by CPBL, this works in Ubuntu 15.04 and later. For older versions try nmcli nm enable false and nmcli nm enable true.

---

Another way very close to your quest is to use:

nmcli dev disconnect iface eth0

To enable eth0 again you need to type:

nmcli -p con up id "<connection name>" iface eth0

Example for connection named "Wired connection 1":

nmcli -p con up id "Wired connection 1" iface eth0

Change eth0 to your wired interface name. This will prevent any further connections without user/manual intervention as man nmci says:

disconnect iface <iface> [--nowait] [--timeout <timeout>]
           Disconnect a device and prevent the device from automatically
           activating further connections without user/manual intervention.
       Available options are:
            --nowait     – exit immediately without waiting for
            command completion

            --timeout    – how long to wait for command completion
            (default is 10 s)

Please read man nmcli for more info.