Exam JN0-231 topic 1 question 14 discussion

Translation of the original source IP address to an IP address from a user-defined address pool by shifting the IP addresses. This type of translation is one-to-one, static, and without port address translation. If the original source IP address range is larger than the IP address range in the user-defined pool, untranslated packets are dropped. https://www.juniper.net/documentation/us/en/software/junos/nat/topics/topic-map/nat-security-source-and-source-pool.html

pool-based NAT with address shifting is correct answer this type of translation is one to one static and without PAT pool-based NAT without PAT the assoiciation between the original source IP Add is dynamic

address shifting" doesn't explicitly rule out the use of PAT, and without more context, it's not clear that this would provide a static translation without PAT.

D. Pool-based NAT without PAT: This is the solution that aligns with your requirement. Pool-based NAT without PAT implies that each internal IP address is statically mapped to a specific external IP address from a pool, without using different port numbers to distinguish between multiple internal hosts. This provides a static, one-to-one translation for each host, which is what you're looking for.

Just think, which one has one to one "static" mapping.

The correct answer is D. pool-based NAT without PAT. In the scenario where you want to provide a static translation without Port Address Translation (PAT), you would use pool-based NAT without PAT. This solution allows for a one-to-one mapping between the internal private IP addresses and external public IP addresses without modifying the port numbers. This is often used when you need to maintain a direct correlation between internal and external IP addresses, which is useful for specific applications or scenarios.

https://www.juniper.net/documentation/us/en/software/junos/nat/topics/topic-map/nat-security-source-and-source-pool.html#id-understanding-source-nat-pools-without-pat