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Layer 2 Switching And VLANshardMultiple ChoiceObjective-mapped

JNCIS-ENT Layer 2 Switching And VLANs Practice Question

An engineer is deploying Selective QinQ where customer inner VLAN tags must be preserved while the outer tag is swapped or added based on ingress port rules. Which Junos statement enables tag preservation?

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 interfaces ge-0/0/0 unit 0 family ethernet-switching input-vlan-map push

When configuring QinQ or VLAN translation, the 'pop' or 'swap' actions with tag preservation are managed via vlan-map configurations using stacking.

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 ge-0/0/0 unit 0 family ethernet-switching input-vlan-map pop

    Why it's wrong here

    Simply popping tags removes them rather than performing selective Q-in-Q mapping with preservation.

  • set interfaces ge-0/0/0 unit 0 family ethernet-switching input-vlan-map push

    Why this is correct

    Correct. The push mapping action adds an outer tag while preserving the inner customer VLAN tag.

  • set interfaces ge-0/0/0 unit 0 family ethernet-switching encapsulation qinq-transparent

    Why it's wrong here

    QinQ transparent mode passes all tagged traffic without outer tag manipulation.

  • set interfaces ge-0/0/0 unit 0 family ethernet-switching vlan-translation preserve-inner

    Why it's wrong here

    VLAN translation syntax uses input-vlan-map and output-vlan-map rules.

Visual reference

Switch VLAN 10 Sales (192.168.10.0/24) PC-A PC-B VLAN 20 HR (192.168.20.0/24) PC-C PC-D Router VLANs isolate traffic — inter-VLAN routing requires a Layer 3 device

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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.