Palo Alto Networks (PANW) Certified Network Security Administrator (PCNSA) Practice Exam

Which source address translation type allows multiple devices to share a single translated source address?

1. Static NAT

2. Dynamic IP

3. Dynamic IP and Port

4. Static IP

The correct answer is: Dynamic IP and Port

The correct answer is Dynamic IP and Port. This type of source address translation, often referred to as Port Address Translation (PAT), allows multiple devices on a local network to share a single public IP address by differentiating traffic using unique port numbers. When traffic from multiple internal devices reaches the NAT device, each outgoing connection is assigned a unique port number in addition to the shared public IP address. This allows the NAT device to keep track of the connections from different internal devices, ensuring that return traffic is routed back correctly to the originating device based on the port number. This capability is particularly useful in environments where IP addresses are limited, enabling efficient utilization of a single external IP address while still allowing multiple devices to communicate with external networks simultaneously. This method also enhances security by hiding internal device IP addresses from external networks. In contrast, the other types of source address translation do not facilitate this shared approach. Static NAT maps one internal IP address to one external IP address without sharing among multiple devices. Dynamic IP uses a pool of public IP addresses but still translates one internal IP address to one public IP address at a time, limiting simultaneous connections. Static IP, similarly, does not allow for shared connections since it would directly map specific internal IPs to fixed public