Some ideas here sounded like they would work... until I read further down the page... people need to know what will universally work (that is for windows, brands of routers, IPs, ports, use or diseuse of Hamachi or PortForward, and other such variables (yes, those are actually variables that can mess up the process of connectivity, I would say that a cinder block wall between you and your router would mess it up, but it messes with connection to the router, which messes with the connection to servers). I reccomend the use of PortForward and Hamachi, mainly because it simplifies everything a lot. PortForward makes your router\'s IP address static, therefore making the use of ports easier. Hamachi kinda makes a connection between computers, and makes connecting to local server games (such as Garry\'s Mod and Minecraft) much easier.
Use Hamachi to find your IPv4 address instead of online \"IP finders\", because I know someone who got hacked via his IP, after he use one (they do work, but some may not necessarily be trustworthy, use with caution).
Test each variable (not physical, code variables!), and let everyone know what works, and what dosen\'t