100-150 Question 67
Single answerA small business has been assigned the public IP range 203.0.113.0/28. The company wants to allow multiple internal devices to access the internet using a single public IP address, while keeping their internal private IP addresses hidden. Which technology should the business implement to achieve this?
- A
Static NAT
- B
Dynamic NAT
- C
Port Address Translation (PAT)
- D
Classless Inter-Domain Routing (CIDR)
Show answer and explanation
Correct answer: C
Explanation
Port Address Translation (PAT) is the most efficient form of NAT for this scenario. It allows multiple devices to share a single public IP address by appending unique port numbers to each connection, effectively hiding the internal private IP addresses. This makes PAT the ideal choice for businesses with limited public IP addresses but a need to connect multiple internal devices to the internet.
- A. Incorrect.
Static NAT maps one private IP address to one public IP address on a one-to-one basis. While it allows devices to access the internet, it does not efficiently support multiple devices using a single public IP, which is the requirement here.
- B. Incorrect.
Dynamic NAT maps a pool of private addresses to a pool of public addresses. However, it still requires multiple public IP addresses and does not fulfill the need to use a single public IP for multiple devices.
- C. Correct.
Port Address Translation (PAT), also known as NAT overload, allows multiple devices on a private network to share a single public IP address by differentiating traffic using unique port numbers. This is the appropriate solution for the scenario described.
- D. Incorrect.
Classless Inter-Domain Routing (CIDR) is a method for IP address allocation and routing optimization. While it is useful for managing IP address spaces, it is not a NAT-related technology and does not address the requirement to share a single public IP address.