Hi all.
I have an Raspberry pi at a friends house connected to his router.
I installed an VPN on the router which is working very well. I can connect to the local ip cameras etc. The only thing is… i cannot connect to the raspberry.
Hi.
Maybe the ip ranges of both networks are the same?
Can you ping the RPI?
The issue can be anywhere. I am pretty sure that there is no specific configuration required for openhab so you just need to verify network connectivity to your raspberry pi. Get your smartphone on data network and then VPN to avoid using the same subnet and try to ssh to the pi and/or access the web gui. Pinging will also help. If unsure get a tcpdump on your pi while trying to access it to see if you can even reach the pi
HTH,
Christos
Thank you guys for your quick replies. I changed my ip so this cant be the problem. I also cannot connect from my smartphone using LTE.
Going to ping the pi. thank you christian and christos 
I’m using a VPN to connect to my home loan and from there I use either the “connect bot” app to ssh into the Raspi or just the browser using my home in address of it. That is working!
Thank you for your replies. The power supply was too weak 
That was the mistake
Didn’t know that VPN needs that much power😉