اتصال به وی پی ان از طریق ترمینال اوبونتو

If you want to interact with NetworkManager from the command line you can use the “nmcli” command.

list all NM connections: nmcli con

start connection (wifi, vpn, etc): nmcli con up id ConnectionName

down connection: nmcli con down id ConnectionName

(more nmcli commands in the nmcli manpage).

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Also note that regular users usually don’t have permission to control networking. Using the commands above with sudo should work for most connections, but VPN specifically might fail with “Error: Connection activation failed: no valid VPN secrets.”

If that happens to you, it’s likely that the VPN password is stored in your user’s gnome-keyring, which makes it inaccessible to the root user. This comment explains why.

To fix this, edit /etc/NetworkManager/system-connections/ConnectionName and under [vpn], change the password flags line to:

password-flags=0

If there is a line starting with Xauth password-flags, change it instead.

Then add the following below the [vpn] block:

[vpn-secrets]
password=YourPassword

(If in the previous step you changed the line Xauth password-flags, add Xauth password=... instead.)

Now restart network manager by:

sudo service network-manager restart

Then starting the VPN connection with sudo nmcli con up id ConnectionName should work without problems.