I just signed up to Nord VPN (I’ve been through the others and it seems like a good option).
Since I deal in drugs and sell guns, etc.*** there’s always a chance that the VPN could drop and expose our real IP.
Seems that we need a monitor for things like Transmission so if the VPN drops for some reason, they go down as well rather than trying to reconnect over the open web. This seems like a job for the development team but probably something worthy of consideration
I note that OpenVPN has a -down option to trigger a script when the tunnel fails - presumably this is the way to do it? Unless there’s a better VPN handler than OpenVPN/PiVPN. I’m using it to tunnel in on one DietPi machine (to my private network) and tunnel out on another machine for privacy purposes.
God I love DietPi!
*** JUST KIDDING! :mrgreen:
Turns out that what I thought was complicated is easier than I thought… sorta.
OK you create a simple shell script to terminate the process(es) you want to kill off if the VPN goes down. There’s probably a more polite way to do this but I’ll wait for someone with more expertise to weigh in here. Let’s say you’re running something like Transmission:
#!/bin/sh
killall transmission-daemon
Which is very quick and dirty, but hey ho… save this somewhere handy and make a note of the location. I’m a complete hack so I dropped it with the configuration files, but it’s hardly an ideal place if you’re more organized. You might even want to make a log entry… but I’m more concerned with preventing leaks of sensitive information, so killing it all as quick as possible is paramount.
Now, find your OpenVPN configuration file in /etc/openvpn and add the following couple of lines to it (this is what mine looks like):
script-security 2
down /etc/openvpn/panic.sh
You can do the same thing with an “up” script but there doesn’t seem any point for this example. Don’t forget to make the script executable though! You should stop anything nefarious you’re doing if the VPN goes down.
An up script will bring things back to life… but a reboot is probably neater. What? I’m lazy… so sue me! 
Also- CHECK IT WORKS! Kill the server process and check what you needed to shut down actually shut down. 
Now there is no need to use NordVPN. You don’t know NordVPN hacked. I can’t believe how NordVPN resorts to blame game and not auditing what is installed on its rented servers. Nord reputation is seriously tainted according to various sources. This is the right time to switch to another VPN. Black Friday is also near to come, and as you all know all providers are offering huge discounts on their products. Check out https://www.vpnranks.com/vpn-deals/, you can explore top 10 providers with their details and deals here as well. 
It’s a pity since otherwise NordVPN has quite good reviews about performance, availability and such. I am also not sure whether to count it as “shit happens to everybody, and when it does, they learn to do better”, or “such thing MUST not happen to any security/privacy company I can trust”. I am just reading so many news lately about banks and other large service providers where contact data sets are suddenly available publicly and such… As tiny defending: Especially large companies are of course preferred hacker target and NordVPN definitely is one of the large ones.