JNCIS-ENT Layer 2 Switching And VLANs Practice Question
On an EX Series switch, you have configured private VLANs (PVLANs) where community VLAN ports need to communicate with a designated promiscuous port, but not with ports in other community VLANs. Which hierarchical configuration is mandatory to bind the primary VLAN and secondary VLANs together?
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
✓
set vlans primary vlan-id 10 private-vlan community [ 20 30 ]
Private VLANs require defining the primary VLAN and associating the secondary VLANs using the 'private-vlan' configuration statement under the [edit vlans] hierarchy.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
set interfaces vlan unit 0 family ethernet-switching pvlan-mapping primary 10 secondary 20
Why it's wrong here
PVLAN mappings are defined under the VLAN configuration hierarchy, not the logical interface family hierarchy.
- ✗
set protocols private-vlan primary-vlan 10 secondary-vlan [ 20 30 ]
Why it's wrong here
Private VLANs are not configured under the protocols hierarchy in Junos.
- ✓
set vlans primary vlan-id 10 private-vlan community [ 20 30 ]
Why this is correct
Correct. The secondary VLANs are associated with the primary VLAN as community or isolated under the [edit vlans <vlan-name>] configuration.
- ✗
set vlans primary-vlan vlan-id 10 isolation-community [ 20 30 ]
Why it's wrong here
This is incorrect syntax for PVLAN associations in Junos.
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 →
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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.