UPnP causes Ports to close instead of open

OK.

Before you start opening up a bunch of ports does your router have a UPnP option.

This should be enabled first before you opt to open any ports.

Having UPnP enabled and ports open can cause conflicts.

Enable UPnP remove any port forwarding and try connecting.

[quote user="Crispyclot"]

Is it normal for NAT to switch like that itself ...?

[/quote]
It usually does that if you have either UPnP issues or port forward issues that cause your Xbox 360 to lose the port assigned by UPnP or manual Port Forward. UPnP is a microsoft proposed feature that has been around since XP. Its a robust method of "auto"
port forwarding. its unsecure because it never closes the ports once they have been opened for a specific device, unlike NAT-PMP (port mapping protocol) that was proposed by Apple.
\
So at one point, it was a port forwarding service war between two big rival software companies and Microsoft won of course.
\
So the point here is that router/modem from actiontec might have a bad UPnP or portforward daemon/service that crashes after sometime, causing Moderate NAT.

Hi,

You don't strictly "need" UPnP, UPnP is just an easy way to let the router open the ports you need for your connected devices. Some implementations of UPnP don't work very well so if UPnP does not work for you - you can just use port forwarding instead

DO NOT enable UPnP and forward ports. It will cause conflicts.

If you have multiple consoles on the same network and are trying to connect to Call of Duty AW,

You need to open additional ports to get an Open NAT.

Disable UPnP and open 3075 along with the other necessary ports for 1 additional console. If you have 2 additional consoles, open 3075 and 3076. UDP

HI there,

-

did you disable UPnP and use opening/forwarding of the ports, or did you disable the ports opening/forwarding and have UPnP on?

Most of the cases when UPnP is available it is better to use that then opening ports.