I have a couple of rather basic questions about NAT translation.
For a simple translation like:
ip nat inside source list ACL interface GigabitEthernet 0 overload
If the traffic does not match ACL, it will go out untranslated. So why not just make ACL
permit ip any any?
In the case which the outside interface is the WAN, it would waste bandwidth if this traffic went out, either translated or un-translated. So, is there a way to block traffic not translated by NAT from going out? I have tried applying an output ACL on the interface but it ended up blocking even NAT translated traffic.