200-201 Question 117
Single answerA company has deployed a NAT/PAT configuration on their edge router to allow internal devices with private IP addresses to communicate with external servers on the internet. One of the internal devices with IP address 192.168.1.10 attempts to access a web server on the internet using TCP port 80. Which of the following is MOST LIKELY to happen when NAT/PAT processes the outgoing request?
- A
The internal IP address 192.168.1.10 is replaced with the router's public IP address, and the source port is dynamically allocated.
- B
The internal IP address 192.168.1.10 is replaced with a static public IP address assigned to that device, and the source port remains unchanged.
- C
The NAT/PAT process blocks the connection because private IP addresses cannot be translated.
- D
The internal IP address 192.168.1.10 is replaced with the router's public IP address, and the source port is statically assigned.
Show answer and explanation
Correct answer: A
Explanation
NAT/PAT allows devices with private IP addresses to access external networks by translating their private IPs into a public IP address (typically the router's public IP) and dynamically assigning unique source ports to each connection. This ensures multiple internal devices can share the same public IP while avoiding port conflicts.
- A. Correct.
This is correct because NAT/PAT dynamically replaces the private IP address with the router's public IP address and dynamically allocates a unique source port for the connection.
- B. Incorrect.
This is incorrect because the scenario describes a dynamic NAT/PAT setup, not a static NAT configuration where specific public IPs are pre-mapped to internal devices.
- C. Incorrect.
This is incorrect because NAT/PAT is specifically designed to allow private IP addresses to access external networks by translating them to public IPs.
- D. Incorrect.
This is incorrect because NAT/PAT dynamically assigns source ports to avoid conflicts with other connections, not statically assigns them.