[SOLVED] OH2 messed up (VPN / mosquitto)

My OH2 is totally messed up since yesterday.
Openhabian, OH2 stable on a raspberry pi2

My (main) problem:

  • mosquitto stopped working
  • VPN stopped working

What did I find out so far:
My Fritzbox somehow messed up the IP adress, so I set the raspberry pi to the previous IP adress (now fixed, previously DHCP).
I see the raspi on my router with a new MAC address, which is potentially the reason for a new IP assingment.

I returned back to a previous SD-card image, without success (same problems).
So it looks like the issue is network related.

My questions:

  1. Why can the MAC address change (same raspi / same interface eth0)?
  2. Does a new MAC Adress have an impact on the generated key (for VPN connection).
    -> So do I have to do the VPN key generation stuff again?
  3. How can I prevent this MAC address change in the future?

Many thanks in advance!

I removed all the old settings from the previous raspi from the fritzbox settings and setup all the port forwarding brand new for the new MAC address.
So VPN is working again. Mosquitto is not yet.
So answer to qwuestion 2 is NO

Still open: 1 and 3