CCNA IP Routing Practice Question
Exhibit
R1# router ospf 1 network 10.1.12.0 0.0.0.255 area 0 ! interface GigabitEthernet0/0 ip address 10.1.12.1 255.255.255.0
You are verifying OSPF operation on router R1. After confirming that OSPF is configured on the correct interfaces, which command should you use next to directly check whether R1 has established a neighbor adjacency with another OSPF router?
⚠ Common exam trap
Avoid confusing route visibility with neighbor status; they are related but distinct concepts.
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
✓
show ip ospf neighbor
The command show ip ospf neighbor directly displays the OSPF neighbor table, showing whether an adjacency has formed, the neighbor's Router ID, and the current state (e.g., FULL). This is the quickest verification step after confirming configurations. The other commands are unrelated to OSPF: show vlan brief displays VLAN assignments, show spanning-tree shows STP topology, and show mac address-table shows the MAC address table. None of these provide any OSPF neighbor information and would only delay troubleshooting.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
show ip ospf neighbor
Why this is correct
show ip ospf neighbor is the correct next step because it directly lists all OSPF neighbors, their Router IDs, interface, and the current adjacency state (such as FULL/DR or 2WAY). This command verifies that the router has successfully formed an OSPF neighbor relationship and detects any state mismatches, making it the definitive tool for OSPF adjacency troubleshooting.
- ✗
show vlan brief
Why it's wrong here
show vlan brief is wrong for verifying OSPF adjacency because it only displays Layer 2 VLAN memberships and the ports assigned to each VLAN. OSPF operates at Layer 3 and uses IP addressing, so this command provides no visibility into whether neighbor routers have exchanged hello packets or reached the FULL state.
When this WOULD be correct
In a question focused on verifying VLAN configurations or troubleshooting Layer 2 connectivity issues, 'show vlan brief' would be the correct command to check if the VLANs are properly set up and operational.
- ✗
show spanning-tree
Why it's wrong here
show spanning-tree is not appropriate here because Spanning Tree Protocol is a Layer 2 loop-prevention mechanism that monitors port roles and states, not OSPF neighbor formation. OSPF adjacency relies on IP reachability and hello communication, so STP output would not indicate whether two routers have become fully adjacent.
When this WOULD be correct
In a different scenario where the question asks for a command to troubleshoot Layer 2 connectivity issues or to verify the status of STP on a switch, 'show spanning-tree' would be the correct answer, as it provides insights into the spanning tree status and potential issues affecting VLANs.
- ✗
show mac address-table
Why it's wrong here
show mac address-table is incorrect for verifying an OSPF neighbor relationship because it only shows Layer 2 MAC-to-port mappings used for Ethernet switching. OSPF adjacency is a Layer 3 routing protocol process, so examining the MAC table cannot confirm hello packet exchange or the OSPF neighbor state.
When this WOULD be correct
If the exam question asked about verifying MAC address learning on a switch or troubleshooting Layer 2 connectivity issues, then 'show mac address-table' would be the correct command to use in that context.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓show ip ospf neighborCorrect answer▾
Why this is correct
show ip ospf neighbor is the correct next step because it directly lists all OSPF neighbors, their Router IDs, interface, and the current adjacency state (such as FULL/DR or 2WAY). This command verifies that the router has successfully formed an OSPF neighbor relationship and detects any state mismatches, making it the definitive tool for OSPF adjacency troubleshooting.
✗show vlan briefWrong answer — click to see why▾
Why this is wrong here
The 'show vlan brief' command displays VLAN information and port assignments, which is unrelated to OSPF neighbor relationships. OSPF operates at Layer 3 and does not depend on VLAN details for adjacency verification.
★ When this WOULD be the correct answer
In a question focused on verifying VLAN configurations or troubleshooting Layer 2 connectivity issues, 'show vlan brief' would be the correct command to check if the VLANs are properly set up and operational.
Why candidates choose this
A student might think that since OSPF runs over IP, checking VLANs could be relevant if OSPF is configured on a VLAN interface (SVI). However, this command does not show OSPF-specific neighbor state or adjacency information.
✗show spanning-treeWrong answer — click to see why▾
Why this is wrong here
The 'show spanning-tree' command provides information about the Spanning Tree Protocol (STP) state of ports, which is a Layer 2 function. OSPF adjacency verification requires Layer 3 neighbor state information, not STP topology.
★ When this WOULD be the correct answer
In a different scenario where the question asks for a command to troubleshoot Layer 2 connectivity issues or to verify the status of STP on a switch, 'show spanning-tree' would be the correct answer, as it provides insights into the spanning tree status and potential issues affecting VLANs.
Why candidates choose this
A student might confuse STP with OSPF because both involve 'neighbor' concepts (STP has designated/root ports, OSPF has neighbor states). However, STP does not show OSPF adjacency details.
✗show mac address-tableWrong answer — click to see why▾
Why this is wrong here
The 'show mac address-table' command displays MAC address entries learned by the switch, which is Layer 2 information. OSPF neighbor relationships are Layer 3 and require IP-based commands to verify.
★ When this WOULD be the correct answer
If the exam question asked about verifying MAC address learning on a switch or troubleshooting Layer 2 connectivity issues, then 'show mac address-table' would be the correct command to use in that context.
Why candidates choose this
A student might think that since OSPF packets are encapsulated in Ethernet frames, checking the MAC table could help verify that OSPF hello packets are being received. However, the MAC table does not indicate OSPF neighbor state or adjacency formation.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
Go deeper
Related to this question
Learn chapter
Interpreting HSRP and VRRP Operational Status
Key term
Router
A router is a networking device that connects different networks together and directs data traffic between them by choosing the best path for data to travel.
Key term
MAC address table
A MAC address table is a data structure stored in a network switch that maps each of its ports to the MAC addresses of connected devices, enabling the switch to forward frames only to the correct destination.
About these practice questions
Courseiva writes every 200-301 question from scratch — 1,389 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 200-301 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 200-301 exam.