JNCIP-ENT IP Multicast Practice Question
A network engineer must implement Anycast RP using MSDP between two data center routers running Junos OS. Which statement correctly describes a core requirement for MSDP peer establishment?
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
✓
MSDP peer addresses must be reachable via standard unicast routing protocols, and TCP port 639 must be allowed.
MSDP sessions run over TCP port 639. Unlike PIM, MSDP peers do not require direct physical connectivity and typically peer using their loopback addresses, requiring an IGP and an underlying unicast route to establish the TCP connection.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
MSDP messages are encapsulated in PIM register packets and sent directly to the multicast group 224.0.0.13.
Why it's wrong here
MSDP uses TCP connections directly between peers, not PIM register encapsulation.
- ✗
MSDP relies on IGMPv3 source filters to exchange active source state information across administrative domains.
Why it's wrong here
IGMPv3 is used between hosts and routers, whereas MSDP is used between RPs to share active source state.
- ✗
MSDP peering sessions require direct physical interface connectivity between the Anycast RP routers.
Why it's wrong here
MSDP peers can be several hops away and typically peer using loopback addresses over TCP.
- ✓
MSDP peer addresses must be reachable via standard unicast routing protocols, and TCP port 639 must be allowed.
Why this is correct
MSDP uses TCP (port 639) for transport, meaning underlying unicast routing must be operational between the peer loopbacks.
Visual reference
About these practice questions
This JNCIP-ENT question is part of Courseiva's 332-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 →
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 JNCIP-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 JNCIP-ENT exam.