JNCIA-SEC Network Address Translation Practice Question
An administrator configures a Source NAT rule-set with 'from zone trust' and 'to zone untrust'. Internal users can successfully browse the internet. Later, a new interface and zone (DMZ) are added, and hosts in the DMZ also need Source NAT to the untrust zone using the same pool. What is the most efficient way to achieve this?
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
✓
Modify the existing rule-set to include the DMZ zone in the 'from zone' statement, or create an additional rule-set for the DMZ zone.
Junos OS allows multiple source zones to be specified in a rule-set using brackets (e.g., 'from zone [ trust dmz ]') or by creating a separate rule-set for the DMZ zone.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Enable global NAT mode under the system hierarchy to automatically apply NAT across all zones.
Why it's wrong here
Junos OS does not have a global automatic NAT mode; all NAT rules must be explicitly defined per zone/rule-set.
- ✗
Delete the trust zone rule-set and recreate it globally without specifying any source zone.
Why it's wrong here
Junos rule-sets require an explicit 'from zone' definition; you cannot omit the source zone.
- ✓
Modify the existing rule-set to include the DMZ zone in the 'from zone' statement, or create an additional rule-set for the DMZ zone.
Why this is correct
Rule-sets can either include multiple source zones or administrators can configure a dedicated rule-set for the new zone referencing the same pool.
- ✗
Configure static routes from the DMZ zone directly to the untrust zone to bypass NAT requirements.
Why it's wrong here
Routing does not bypass security zone NAT requirements.
Visual reference
About these practice questions
This JNCIA-SEC question is part of Courseiva's 513-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam 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.