The correct interpretation is that the OSPF adjacency is fully established, confirming that CoPP is not dropping Hello packets or any other OSPF traffic. This debug output shows the complete adjacency formation process—from receiving a Hello packet and establishing two-way communication, through the Database Description (DBD) exchange, to the FULL state—which proves that Control Plane Policing policies are permitting OSPF packets to reach the router’s control plane. On the Cisco CCNP ENARSI 300-410 exam, this scenario tests your ability to correlate debug output with CoPP functionality; a common trap is assuming any debug message indicates a problem, when in fact the progression to FULL state is the definitive sign of success. Remember that CoPP drops would manifest as missing Hello packets or a stuck state like INIT or EXSTART, not a clean transition to FULL. A useful memory tip: “FULL state means CoPP is not null”—if you see FULL, CoPP is allowing the flow.
300-410 Control Plane Policing (CoPP) Practice Question
This 300-410 practice question tests your understanding of control plane policing (copp). The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 network engineer runs the following command to troubleshoot a Control Plane Policing (CoPP) issue:
R1# debug ip ospf adj
OSPF adjacency debugging is on
R1#
*Mar 1 00:05:23.123: OSPF: Rcv pkt from 10.1.1.2, FastEthernet0/0, area 0.0.0.0, packet type: 1 (Hello)
*Mar 1 00:05:23.123: OSPF: 2 Way Communication to 10.1.1.2 on FastEthernet0/0, state 2WAY
*Mar 1 00:05:23.124: OSPF: Send immediate hello to nbr 10.1.1.2, src address 10.1.1.1, on FastEthernet0/0
*Mar 1 00:05:23.124: OSPF: Rcv pkt from 10.1.1.2, FastEthernet0/0, area 0.0.0.0, packet type: 2 (DBD)
*Mar 1 00:05:23.125: OSPF: Rcv DBD from 10.1.1.2, seq 0x1234, opts 0x2, flag 0x7, mtu 1500 state EXSTART
*Mar 1 00:05:23.126: OSPF: Nbr 10.1.1.2 has state FULL
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
OSPF adjacency is established successfully, indicating CoPP is not blocking OSPF traffic.
The debug output shows OSPF adjacency formation with neighbor 10.1.1.2. The sequence of packets (Hello, DBD) and the transition to FULL state indicate that the adjacency is established successfully. This can be used to verify that CoPP is not dropping OSPF packets.
Key principle: OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
OSPF adjacency is failing due to CoPP dropping Hello packets.
Why it's wrong here
The output shows successful Hello exchange and transition to FULL state.
✓
OSPF adjacency is established successfully, indicating CoPP is not blocking OSPF traffic.
Why this is correct
The adjacency reached FULL state, meaning OSPF packets are being processed correctly.
OSPF is experiencing packet loss due to MTU mismatch.
Why it's wrong here
The MTU of 1500 is mentioned, but no errors are indicated.
✗
OSPF is stuck in EXSTART state due to CoPP.
Why it's wrong here
The output shows transition from EXSTART to FULL.
Common exam traps
Common exam trap: OSPF can fail even when IP connectivity looks correct
OSPF neighbour formation depends on matching areas, timers, network type, authentication and passive-interface behaviour. Do not choose an answer only because the devices can ping.
Trap categories for this question
Command / output trap
The output shows successful Hello exchange and transition to FULL state.
Detailed technical explanation
How to think about this question
OSPF questions usually test the details that control adjacency and route selection. Read the neighbour state, area, router ID and interface configuration before deciding what is wrong.
KKey Concepts to Remember
OSPF neighbours must agree on key parameters.
Router ID selection can affect neighbour relationships and LSDB output.
OSPF cost influences the preferred path.
A route can appear in OSPF information but not become the installed route.
TExam Day Tips
→Check area mismatch first when OSPF adjacency fails.
→Review passive interfaces when a network is advertised but no neighbour forms.
→Use show ip ospf neighbor and show ip route clues carefully.
Key takeaway
OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.
Real-world example
How this comes up in practice
A network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 300-410 question in full detail.
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related 300-410 OSPF questions on adjacency and route selection.
Control Plane Policing (CoPP) — This question tests Control Plane Policing (CoPP) — OSPF neighbours must agree on key parameters..
What is the correct answer to this question?
The correct answer is: OSPF adjacency is established successfully, indicating CoPP is not blocking OSPF traffic. — The debug output shows OSPF adjacency formation with neighbor 10.1.1.2. The sequence of packets (Hello, DBD) and the transition to FULL state indicate that the adjacency is established successfully. This can be used to verify that CoPP is not dropping OSPF packets.
What should I do if I get this 300-410 question wrong?
Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related 300-410 OSPF questions on adjacency and route selection.
What is the key concept behind this question?
OSPF neighbours must agree on key parameters.
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.