Cisco Certified Network Associate (CCNA) Practice Exam

Which NAT term identifies a public IP address visible to external networks?

1. Outside local

2. Inside local

3. Inside global

4. Outside global

The correct answer is: Inside global

The term that identifies a public IP address visible to external networks is "Inside global." This classification refers specifically to the IP address assigned to an internal device that is used for communication on external networks, such as the internet. In the context of Network Address Translation (NAT), when a device on a private network (with a private IP address) communicates with external networks, its private IP address is replaced with an inside global address, which is a routable public IP address. This allows devices on the public internet to reach the device on the internal network while keeping the internal IP secure and hidden. The other options refer to different types of addresses in the NAT framework. For example, "Outside local" identifies an address that is used by an external device to refer to an internal device, which may not be a routable IP. "Inside local" pertains to the private IP address of a device within a local area network, and "Outside global" corresponds to the actual public address assigned to an external device. Therefore, "Inside global" is the correct term for a public IP address that bridges communication between internal networks and external networks.