Global NAT address persistence is a feature configured on a source NAT pool. When enabled, it ensures that the Junos device assigns the same translated IP address from the pool for all sessions originating from a specific internal host's IP address. This creates a consistent, or "sticky," mapping between an internal IP and its translated external IP, which is maintained for as long as at least one active session for that host exists.

B: This statement describes the default behavior when address persistence is not enabled. Without persistence, a different IP from the pool can be used for different sessions.

C: The "address-persistence" feature, as defined and configured in Junos OS, applies specifically to source NAT pools, not destination NAT pools.

D: This option is incorrect because it refers to a destination NAT pool and describes non-persistent behavior, which is contrary to the purpose of the feature.

1. Juniper Networks TechLibrary

"Understanding NAT Address Persistence": "Address persistence enables the device to use the same mapped IP address for all sessions from a particular internal IP address... With address persistence enabled for a source NAT pool

for a given original source IP address

the same translated source IP address is allocated for all sessions."

URL: https://www.juniper.net/documentation/us/en/software/junos/nat/topics/concept/nat-address-persistence-understanding.html

2. Juniper Networks TechLibrary

"address-persistence (Security Source NAT)": This configuration guide shows that address-persistence is a statement configured under the [edit security nat source pool pool-name] hierarchy.

URL: https://www.juniper.net/documentation/us/en/software/junos/nat/topics/ref/statement/security-edit-address-persistence.html