I was only unsure of it because it said "DMZ Host IP Address" , so i didn't know what address to put. That has nothing to do with me port forwarding before. First i went with IPv4 and when i saw it didn't work i tried with everything else i can find.
Before this all i had to do was set a static ip address and type in a port that i want to open. But now i searched 100 forums about this, and haven't found a single thread that resembles my problem and has been solved...
I don't see a reason behind posting my lan address when you say i shouldn't use it for anything...
About my ISP, i have been with them for many years, and not once did i had this problem. So if they weren't blocking anything for 5+ years, why would they start now... And also this is the same modem/router i had before, that had ports opened...
I have found something about setting a static ip address in my WAN settings, do you think that might have something to do with my problem? Because i can't getting it to work, keeps reporting duplicate ip, and i didn't want to search anymore..