Dedicated server joining problem

Hello people,
I have a dedicated server for some weeks now, but I have now the problem that not everyone of my friends can join, just a few. They get the error: Server is not responding. I have the ports forwarded and my firewall is deactivated, I have no idea what to do. I tried everything :frowning:
I will add a picture of my config and my console to this thread.

http://puu.sh/a8jlp/c5597e9077.png

http://puu.sh/a8jlp/c5597e9077.png

And sorry for my bad english, Iā€™m from germany :slight_smile: