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JNCIS-ENT OSPF Practice Question

A Junos router running OSPF is configured with graceful restart helper mode enabled. What is the primary role of an OSPF graceful restart helper router during a control plane restart of a neighboring router?

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

To maintain neighbor adjacencies and continue forwarding packets without recalculating the SPF tree while the neighbor restarts

Helper routers continue forwarding traffic based on existing routes and assist the restarting router by maintaining adjacencies and suppressing LSA re-origination until the restarting control plane recovers.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • To translate Type 7 LSAs into Type 5 LSAs during the helper window

    Why it's wrong here

    Incorrect. This is an NSSA ABR function, unrelated to graceful restart.

  • To maintain neighbor adjacencies and continue forwarding packets without recalculating the SPF tree while the neighbor restarts

    Why this is correct

    Correct. Helper mode maintains forwarding and holds adjacency state during a peer's restart.

  • To purge all LSAs originated by the restarting router from the LSDB

    Why it's wrong here

    Incorrect. Purging LSAs would disrupt traffic; helper mode specifically prevents this.

  • To take over the role of Designated Router immediately upon detecting control plane failure

    Why it's wrong here

    Incorrect. Helper mode does not alter DR/BDR election logic or force immediate takeover.

Visual reference

R1 R2 R3 R4 10 100 10 100 OSPF picks R1→R2→R4 (cost 20) over R1→R3→R4 (cost 200)

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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.