Well, I'm into networks and so, and i recommend using port forwarding, and no, that doesn't mean you have to give your friends your IP adress every time your router changes it ( default: 1 day time), you just log in your router, go to port forwarding, port forward 25565 to your internal ip adress (you can find that out on your router aswell, or just ipconfig in command prompt on your computer), if you don't know how to port forward, there is this neat site: http://portforward.com/ where you just find your router, and he shows you the guide for that router specificaly. Then you find the dynamic DNS updater on your router, and set up an account. That way, you give your friends an adress instead of an ip, that is the same every time, no matter what your external IP adress is. ex. ilovetekkit.dyndns.pro I recommend using http://www.changeip.com/ they are reliable. If you need help, let me know, PM me or smth