Which statement best differentiates static NAT from dynamic NAT?

• A. Dynamic NAT maps a private IP to a fixed public IP; Static NAT uses a pool of public addresses assigned as needed.
• B. Static NAT maps a private IP to a fixed public IP; Dynamic NAT uses a pool of public addresses assigned as needed.
• C. Static NAT maps a private IP to a temporary public IP; Dynamic NAT uses a pool of private addresses.
• D. Dynamic NAT maps a private IP to a fixed public IP; Static NAT uses a pool.

Answer: (B)

The key distinction is how addresses are assigned from the public side. Static NAT creates a permanent one-to-one mapping between a private IP and a specific public IP, so that internal devices always appear with the same public address to the outside world. This predictability is why static NAT is often used for servers that must be reachable at a fixed address.

Dynamic NAT, on the other hand, uses a pool of public addresses. When an internal device communicates outward, the gateway borrows an available public IP from the pool for the duration of that session. The mapping is temporary; once the session ends, that public address goes back into the pool and can be reassigned to another device. This setup lets many internal hosts share a limited number of public addresses, but the outward address for a given host can change over time.

The other statements mix up fixed versus pooled addressing or private versus public addresses, which would not reflect how NAT translates private addresses to public ones.