Hi Udo thanks! Unfortunately I am not quite sure what you are needing as there is a VPN test paragraph in the article under ‘Test for a VPN Connection’. Just go through that and take note of the ‘hop count’ when your VPN is connected and active. If in the future if you suspect the VPN is down, run the same ‘traceroute [web site]‘ command again and take note of its hop count. If it is a similar number to your previous tests the connection is active, if it is significantly less then the VPN is down.
The traceroute tells you how many (hop count) servers a web request needs to pass through to reach the destination website from your computer. If a VPN is active your traceroute hop count will be much higher as a request first detours to the VPN before forwarding the request to the destination website.