JNCIA-SEC Network Address Translation Practice Question
You are troubleshooting a Destination NAT rule where traffic matching the rule is dropped. You run 'Traceoptions' for security flow and notice that the packet hits the destination NAT rule, translates successfully, but then fails. Examining the trace output reveals: 'No route found: 10.1.1.50 -> 0.0.0.0'. What is the underlying cause?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The routing table lacks a valid route to the post-translation internal IP address.
After Destination NAT translates the destination IP address to an internal private IP, the SRX performs a route lookup on the post-translation destination IP address to determine the egress interface and next hop. If no route exists for the translated IP, the packet is dropped.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Proxy ARP is not enabled on the internal server interface.
Why it's wrong here
Proxy ARP is for external interfaces facing upstream routers, not internal routing lookups on SRX.
- ✓
The routing table lacks a valid route to the post-translation internal IP address.
Why this is correct
Destination NAT requires a valid route to the post-translation address for the packet to be forwarded.
- ✗
The security policy is missing the pre-translation public IP address in the destination field.
Why it's wrong here
Security policies evaluate post-translation destination IPs, not pre-translation ones.
- ✗
The destination NAT pool port translation is misaligned with the server listening port.
Why it's wrong here
Port mismatch would cause application handshake failure, not a routing lookup failure ('No route found').
Visual reference
About these practice questions
Courseiva writes every JNCIA-SEC question from scratch — 513 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official Juniper Networks exam blueprint
This JNCIA-SEC practice question is part of Courseiva's free Juniper Networks certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the JNCIA-SEC exam.