I solved the problem.
I am using cox and they are blocking port 80. Well now I am using https and port 443 and everything works fine!
Question
I'm now having problems with this for over a week. I'm running a minecraft server on my computer. Therefore I used no-ip.org to have a "fixed" ip. I forwared all ports for the server and my friends can access without any problems. Later I thought I could make a little Homegape for statistics and stuff. So I installed xampp. I forwarded the ports 80, 8080, 8000, 7171. I (and everybody else in my local network) can access it via the no-ip.org address. But nobody else! (And I want to repeat that people can reach my computer over the minecraft port (25565) and no other port!)
How can I fix that problem? I'm pretty sure there is a simple node in one of the config's which I haven't seen yet. I googled for days. So I found out that I should forward these ports. But that's all I could find.
My firewall is (for testing of course!) disabled!
Solution 2
I solved the problem.
I am using cox and they are blocking port 80. Well now I am using https and port 443 and everything works fine!
OTHER TIPS
Probably your firewall is blocking xampp or apache. If you are at windows 7, try to go to Control Panel -> System Security -> windows firewal > allow a program through windows firewall and then search "apache" or "xampp" and mark to allow public and private connections
Additionally you can try this also: