The answer is that the spoke is missing the 'ip nhrp map multicast dynamic' command. This command is essential because, in a DMVPN Phase 2 or Phase 3 network, the spoke must dynamically register its real interface (the tunnel source) with the hub NHS (10.0.0.1). Without it, the spoke cannot send NHRP registration packets to the hub, nor can it receive multicast or broadcast traffic—such as routing protocol hellos or dynamic routing updates—from the hub over the mGRE tunnel. On the Cisco CCNP ENARSI 300-410 exam, this is a classic configuration gap that tests your understanding of NHRP registration mechanics; a common trap is to assume that a static 'ip nhrp map' for the NHS alone is sufficient. Remember the memory tip: "No multicast dynamic, no registration—your spoke stays silent."
300-410 DMVPN Practice Question
This 300-410 practice question tests your understanding of dmvpn. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A spoke router has the following DMVPN configuration:
interface Tunnel0
ip address 10.0.0.2 255.255.255.0
ip nhrp network-id 100
ip nhrp nhs 10.0.0.1
tunnel source GigabitEthernet0/0
tunnel mode gre multipoint
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The spoke is missing the 'ip nhrp map multicast dynamic' command to register with the hub.
In DMVPN Phase 2/3, spokes need to register with the NHS. The command 'ip nhrp map multicast dynamic' or a static multicast map is required for the spoke to send NHRP registration and receive multicast from the hub.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
The spoke is missing the 'ip nhrp map multicast dynamic' command to register with the hub.
Why this is correct
Without multicast mapping, the spoke cannot send NHRP registration or receive routing updates via multicast.
Related concept
Read the scenario before looking for a memorised answer.
✗
The spoke is missing the 'ip nhrp authentication' command.
Why it's wrong here
Authentication is optional; the spoke can still register without it if the hub does not require it.
✗
The spoke is missing the 'tunnel key' command.
Why it's wrong here
Tunnel key is not required for basic DMVPN operation.
✗
The spoke is missing the 'ip nhrp holdtime' command.
Why it's wrong here
Holdtime is optional and defaults to 3600 seconds.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
Use explanations to understand the rule behind the answer.
TExam Day Tips
→Underline the problem statement mentally.
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 300-410 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 300-410 question in full detail.
Identify which 300-410 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
DMVPN — This question tests DMVPN — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The spoke is missing the 'ip nhrp map multicast dynamic' command to register with the hub. — In DMVPN Phase 2/3, spokes need to register with the NHS. The command 'ip nhrp map multicast dynamic' or a static multicast map is required for the spoke to send NHRP registration and receive multicast from the hub.
What should I do if I get this 300-410 question wrong?
Identify which 300-410 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This 300-410 practice question is part of Courseiva's free Cisco 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 300-410 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.