Seems to work between 2 machines, but as I started the script again at the server with the configuration for the second client and started the same script at the second client they couldn't communicate between each other at all.

Due to the circumstance that this really was our live server and the client was a live server, too, I didn't know to help me but to reboot both machines. Ok, I'm still CTO of this company, but if I do this a second time I may need a new place to work...

Obviously it's not good to start the same script more than once at the server. What did I wrong? And how do I switch everything back without rebooting the whole machine?

Wow, what a day.

Rolf