Watchguard Network Security Practice Test

For forwarding inbound traffic to internal hosts based on the destination port, which type of NAT should be used?

1. Static NAT

2. 1-to-1 NAT

3. Dynamic NAT

4. Policy-based NAT

The correct answer is: 1-to-1 NAT

The correct answer focuses on using Policy-based NAT for forwarding inbound traffic to internal hosts based on the destination port. Policy-based NAT allows for more granular control of network traffic. It enables administrators to create specific rules that can match against various parameters, including destination ports, source address, and even protocol types. In scenarios where different internal hosts provide different services on the same interface, such as web servers on different ports, Policy-based NAT allows you to apply specific rules for each service. For example, if external traffic is directed to a web server on port 80 and a mail server on port 25, policy-based NAT can distinguish between these different types of traffic and correctly forward them to the respective internal hosts. The other NAT types mentioned, such as Static NAT and 1-to-1 NAT, are not as flexible when it comes to rules that rely on destination ports and are primarily used for straightforward address translation without the same level of control. Meanwhile, Dynamic NAT is designed to map internal addresses to an external address from a pool of addresses as needed, which does not suit the requirement for destination-based forwarding. Thus, the effectiveness of Policy-based NAT in allowing specific configurations for forwarding traffic based on destination ports makes it the appropriate choice.