Systems Security Certified Practitioner (SSCP) — Question 128

Upon which of the following ISO/OSI layers does network address translation operate?

Answer options

• A. Transport layer
• B. Session layer
• C. Data link layer
• D. Network layer

Correct answer: D

Explanation

Network address translation (NAT) operates at the Network layer (Layer 3) of the ISO/OSI model, where it modifies the IP address information in packet headers. The other layers, such as Transport (Layer 4), Session (Layer 5), and Data Link (Layer 2), do not handle IP addressing and routing, which are the primary functions of the Network layer.