So, my ISP uses a modem called a ZyXEL Prestige 660-T1 to connect to the Internet. One day - I got tired of my parents asking me to let them use my computer, so we got a router to put together with the modem, specifically a ZyXEL Prestige P-320W.
It used to forward ports nicely, I could host games, and I tried using the uTorrent port tester (no, I didn't download anything, just the website port checker) and it worked.
Suddenly, something wierd happened. I don't know - it started some time ago that the port forwarding stopped working. That time, I was still able to host games, but recently even the ability to host games also got ripped away.
Connecting to the modem to try setting up port forwarding there ... is quite impossible - the modem is set to 'Bridge', meaning it doesnt send data auto to my computer, it sends it to the router first.
Also, the modem probably has some configuration in it - so I don't dare to reset it. I can reset the router a million times though, messed with it frequent enough.