200-301 Question 359
Single answerA network administrator is configuring NAT on a router to allow internal hosts to communicate with external networks using a single public IP address. The administrator wants to ensure that internal hosts have a consistent mapping to the same external IP address. Which configuration method should the administrator use?
- A
Dynamic NAT with a pool of public addresses
- B
Static NAT with a single public IP address
- C
PAT (Port Address Translation) using a single public IP address
- D
Dynamic NAT with overload enabled
Show answer and explanation
Correct answer: B
Explanation
Static NAT with a single public IP address is the best solution in this scenario because it provides a fixed one-to-one mapping between an internal IP and an external IP. This ensures that the same internal host always maps to the same external IP, which meets the administrator's requirement for consistency.
- A. Incorrect.
Dynamic NAT with a pool of public addresses uses a range of IP addresses and does not ensure a consistent mapping for internal hosts. The mapping may change depending on the availability of addresses in the pool.
- B. Correct.
Static NAT with a single public IP address ensures a consistent one-to-one mapping between an internal IP and a single public IP. This is the correct choice for the administrator's requirement.
- C. Incorrect.
PAT (Port Address Translation) uses a single public IP address but differentiates hosts using port numbers. It does not provide a consistent one-to-one mapping as required in this scenario.
- D. Incorrect.
Dynamic NAT with overload enabled is another name for PAT and similarly does not provide a consistent mapping. It maps multiple internal IPs to a single public IP using port numbers.