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.