JNCIS-ENT Protocol Independent Routing Practice Question
An administrator implements filter-based forwarding and applies a firewall filter on the ingress interface. However, traffic matching the filter is dropped rather than routed to the alternate routing instance. Upon investigation, what is the most likely cause of this issue?
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 destination IP address does not have a matching route in the alternate routing instance's table.
If the routing instance specified in the firewall filter action does not have an active route for the destination, the packet is discarded.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The ingress interface is configured as a trunk port.
Why it's wrong here
Trunk ports support FBF as long as logical unit filters are applied correctly.
- ✓
The destination IP address does not have a matching route in the alternate routing instance's table.
Why this is correct
FBF redirects the packet lookup to a specific routing instance's table; if no route matches, the packet is dropped.
- ✗
The firewall filter term lacks a 'count' action statement.
Why it's wrong here
Counting is for telemetry and has no impact on forwarding behavior.
- ✗
The routing instance type is set to virtual-router instead of forwarding.
Why it's wrong here
A virtual-router instance type actually supports full routing tables and routes, making drops less likely than a misconfigured forwarding instance.
Visual reference
About these practice questions
Courseiva writes every JNCIS-ENT question from scratch — 506 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 JNCIS-ENT 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 JNCIS-ENT exam.