oreeh:
Thanks again and sorry for being so "stupid".
I try to rephrase my question:
What do I have to do on both sides to:
\- Give the guest a static IP: 192.168.15.2
\- Give the host a static IP for the guest to communicate with: 192.168.15.5
\- Allow the guest to access the Internet through the host
Exact steps on both sides would be great. (How do I add that route..?)