What command is used to identify an interface as part of the external global network in NAT or PAT configuration?

In Network Address Translation (NAT) or Port Address Translation (PAT) configuration, the command used to identify an interface as part of the external global network is "ip nat outside." This command signifies that the specified interface connects to the public network (the Internet), where the external, routable IP addresses are utilized.

Designating an interface as "outside" is crucial in distinguishing between internal traffic, which is typically translated to use private IP addresses, and external traffic, which interacts with public networks. This differentiation aids the router in determining how to handle packets as they enter or exit the network, allowing proper NAT translation to occur.

The other options do not fulfill the same purpose. For instance, "ip nat inside" is used for interfaces connected to the internal network, where private IP addresses are assigned. Commands like "ip nat global" and "ip nat enable" do not exist in common NAT configuration syntax and would not appropriately identify an interface for NAT functions. Thus, the correct command is essential for properly setting up NAT and ensuring effective communication between internal and external networks.