Automatically Disconnect When Switching Between VPNs

This is step-eliminating enhancement that would be easy to implement.

Where's the best place to submit this proposal?

This is the best idea ever. Can I get some love?

I was able to implement this functionality for myself using autokey-gtk:
sudo apt-get install autokey-gtk

Essentially, I added a folder in the left-pane of Autokey and associated a hot-key with that folder. Then, under that folder I added 3 scripts to facilitate easier switching between the 3 VPNs I frequent through out my work day. Each script only contains one line.

Script 1 - Switch to VPN 1:

os.system("nmcli con down id 'VPN 2' ; nmcli con down id 'VPN 3' ; nmcli con up id 'VPN 1' &")

Script 2 - Switch to VPN 2:

os.system("nmcli con down id 'VPN 1' ; nmcli con down id 'VPN 3' ; nmcli con up id 'VPN 2' &")

Script 3 - Switch to VPN 3:

os.system("nmcli con down id 'VPN 1' ; nmcli con down id 'VPN 2' ; nmcli con up id 'VPN 3' &")

Now, anytime I hit this hot-key combination I've set, a context menu jumps under my mouse-cursor listing all 3 VPNs. When I click any particular one, it automatically disconnects from any of the other two and connects to the one I've selected.

Unfortunately, I was unable to find a nmcli command capable of disconnecting "all VPNs" that might be currently connected. Instead you have to specify the id of the vpn you want to disconnect. I understand the need to specify an id for connection, but I wish there was a general kill all for disconnecting.

I will try to propose this addition to the nmcli command and post back here at some point.

I've posted the idea of:

nmcli con down allvpn

to a separate proposal:
https://bugs.launchpad.net/ubuntu/+source/network-manager-vpnc/+bug/1338382

The bug on this page (1215262), should focus on the gui aspects of implementing this same functionality.

I'm not entirely certain the graphical representation you are seeing is due to any limitation in Network Manager. While I agree there should be a disconnect all option for VPNs, I'm able to see and select multiple VPNs to connect to in the UI, and in some cases I would NOT like to have it force disconnect one connection to connect to another. What you may be seeing is a common issue where if you don't specify the name of the adapter to use (defaults to 'tun') then it trips over itself reusing the same name over and over for each connection. Simply changing the device name (it will create it when necessary as long as you have enough permissions) will allow you to have multiple connections and activate them at the same time.