JNCIS-ENT Tunnels Practice Question

When configuring an IP-IP tunnel on Junos, can you run multicast routing protocols like PIM over the IP-IP tunnel?

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

✓

No, because IP-IP does not support multicast or broadcast packet encapsulation, whereas GRE does.

Unlike GRE, standard IP-IP encapsulation does not support broadcast or multicast traffic natively because IP-IP is strictly point-to-point unicast encapsulation without multicast destination mapping capabilities.

Answer analysis

Option-by-option breakdown

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

✗
Yes, by enabling PIM sparse-mode directly on the ip-0/0/0 interface.
Why it's wrong here
IP-IP does not support multicast traffic forwarding.
✗
No, because Junos prohibits all routing protocols over IP-IP interfaces.
Why it's wrong here
Unicast routing protocols like OSPF and BGP operate successfully over IP-IP tunnels.
✓
No, because IP-IP does not support multicast or broadcast packet encapsulation, whereas GRE does.
Why this is correct
IP-IP tunnels only encapsulate unicast IPv4 packets, making multicast protocols like PIM unusable over IP-IP.
✗
Yes, but only if IGMP version 3 is explicitly configured.
Why it's wrong here
IGMP does not resolve the lack of multicast support in IP-IP encapsulation.

About these practice questions

This JNCIS-ENT question is part of Courseiva's 506-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 →

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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

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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.