Halo 3 How Do I Make My NAT is Open?

[hbk_619_fan]

It says it is on Moderate I have a Linksys Router if that matters I would appreciate a step by step tutorial or at least a link to how I can make it open?
Also it says in the more info that i should enable UPnP and I checked and it is already enabled???

 

[dan]

Take off the firewall on the connection and it will become open.

 

[Ellaa]

shut the firewall down