This is unrelated to bug fixing, but before I did actually google what "NAT" was, it's short for "Network access type" - and in some cases with gaming consoles is restrictive to what can be said, done, or played even. Assuming from the "punch through failed" I'm guessing that your network access type is restrictive to dragon commander. In no way am I going to be able to trouble shoot this without googling it so your on your own. :P
However I doubt it's fixable with port forwarding.
