MW3 NAT

[smartyturk]

Well, I usually have NAT on moderate but when i use any of server mini hacks, like for 1 hour later, my steam shuts it self and game freeze. anyway after i relog on to steam and open mw3 my NAT goes to strict. why??
i have fast internet, i watch so many youtube videos done everything but nope nothing works

some1 please help

[abaaaabbbb63]

You have to open ports.