1. Did you port forward?
2. Console.log
The odds are your server isn't starting on the port you forwarded. Usually what happens for me is it'll start on 28100 and I don't realize this, so I switch it back to 28000, but then it will automatically change to 28100 because 28000 is taken by something. Since my system has ports 28100 forwarded for another software I can't use those ports, so what I have to do at this point is port forward a new port. I use 28200. Then I go into advanced and change the port from 28100 to 28200. Hope that makes sense.