Which NAT type maps a private address to a fixed public address?

• A. Dynamic NAT maps a private address to a public address on a pool.
• B. Static NAT maps a fixed private address to a public address.
• C. PAT maps many private addresses to a single public address using ports.
• D. NAT does not modify IP addresses in any way.

Answer: (B)

Static NAT provides a fixed one-to-one mapping between a private IP and a public IP. This means a specific internal device always appears on the internet with the same public address, which is essential for services that must be consistently reachable from outside.

Dynamic NAT, in contrast, assigns a public address from a pool for the duration of a session, so the same private address may map to different public addresses over time. PAT (port address translation) lets many private addresses share a single public IP by using different ports, so it is not a one-to-one, fixed mapping. NAT modifies addresses as traffic passes through, which is why the statement that NAT doesn’t modify IP addresses isn’t correct.