Today I was playing Modern Warfare 2. I was hosting ground war. There were something like 20 people playing. A notoroius blatant hacker joined. I wanted to get rid of him. My idea was to start adding ports to my firewall to find him and block him out.
When I opened up netstat this is what I found.
The last entry is immediately after I quit the game. The last IP shown belongs to steam.
How does MW2 hide all the incoming connections from netstat?
How can I overcome this?
It'll be using UDP not TCP, so won't have fixed connections. Unfortunately you're not going to be able to find his IP from netstat for UDP; you'll have to look it up in-game.
To get more useful information from netstat, you wanted netstat -ano: that'll also show your open UDP listen sockets and the program IDs that own each one. You can then use task manager (view, select columns, add PID column) to identify which ones are owned by MW2. But UDP doesn't have fixed connections so it won't show information about who externally is using your UDP connections.