"connect" button in NetPlay doesn't work for me, neither does hosting

[TheBral]

Whenever I get a code from someone else and enter it, the connect button just stops, waits for a moment, and then does nothing when I click it. When I try to host someone else, they can't enter with me either. I must have setup dolphin wrong, right? Do I need to port forward if I'm not using the direct connect? Could someone give me a tutorial for dolphin 5.0 because I've followed a lot of them and it still doesn't work. Please help me. Thanks and let me know if you need any more information.