Juniper JN0-637 Exam Questions & Answers

Correct Answer: BD

Persistent NAT with target-host restricts session initiation to specific addresses, enhancing security. Reflexive NAT supports multiple connections by preserving the original port. Refer to Juniper NAT Configuration Documentation.

Referring to the NAT configuration shown in the exhibit:

Specific Host Can Initiate a Session (Answer B): The configuration uses persistent NAT with the permit target-host-port statement. This allows a specific external host (based on the target host and port used in the initial session) to initiate a

session back to the internal host after the initial session has been established.

Persistent NAT ensures that the translation state is maintained, allowing external hosts to connect back only under specific conditions (e.g., the same target host and port as used in the original connection). Original Destination Port (Answer

D): The original destination port used by the internal host is retained as the source port when the session is established from outside to inside. This behavior is a result of how persistent NAT binds the internal and external sessions, ensuring

that communication occurs over the same port used for the initial session.

Correct Answer: D

The exhibit describes a Chassis Cluster configuration with high availability (HA) settings. The key information is related to Service Redundancy Group 1 (SRG1) and its failover behavior between the two peers.

of Answer D (Packet Forwarding after Failover):

In a typical SRX HA setup with active/backup configuration , if the SRG1 group moves to peer 2 (the backup), peer 1 (previously the active node) will forward packets to peer 2 instead of dropping them. This ensures smooth failover and

seamless continuation of services without packet loss.

This behavior is part of the active/backup failover process in SRX chassis clusters, where the standby peer takes over traffic processing without disruption.

Juniper Security Reference:

Chassis Cluster Failover Behavior: When a service redundancy group fails over to the backup peer, the previously active peer forwards traffic to the new active node. Reference: Juniper Chassis Cluster Documentation.

Correct Answer: AD

In multinode HA, the active node retains its role and maintains the active signal route even if the ICL link fails, as long as a backup signal route IP is configured. This backup ensures continuity in failover scenarios. For detailed information,

refer to Juniper Multinode HA Documentation.

In a multinode HA (High Availability) deployment with SRX devices, the Inter-Chassis Link (ICL) is critical for communication between the active and backup nodes. If the ICL link fails, the system relies on thebackup signal route to continue

monitoring the state of the HA deployment.

of Answer A (Active Node Retains Active Role):

If the ICL link fails but the backup signal route is still operational, the active node will retain its role as the active node. This is because the signal route allows the active node to confirm its operational state.

of Answer D (Active Node Keeps Signal Route):

The active node will maintain the signal route if the backup signal route remains operational. The backup node will not preemptively take over the active role unless it detects that the active node has failed entirely.

Juniper Security Reference:

Multinode HA Overview: The backup signal route in multinode HA ensures that the active node retains control as long as it can maintain a signal route. Reference: Juniper HA Documentation.