The multiplayer section of MW2 tells me that my NAT Type is Strict. So I set the DMZ on my router to allow the IP of my Xbox through and it now says the my NAT is Open. Great. But then I realised that my XBox had a Dynamic IP which would change at some point and disable the DMZ. So I changed it to a static IP using identical settings. I then connected to XBox Live and loaded MW2. It now says my NAT is Strict again. It appears that even though the settings are identical my NAT type changes depending on whether it's using a dynamic or static IP, even when those IPs are the same. My DMZ is set to 192.168.0.197. When the IP on the XBOX is manually set to 192.168.0.197 the NAT is strict, but if I switch to automatic and it selects 192.168.0.197 itself, the NAT is Open. Does anyone have any idea what's going on here?