- A
Clear the MAC address table with 'clear mac address-table dynamic' to force immediate relearning.
Why wrong: The default MAC aging time is 300 seconds, so aging is not the issue for a recently connected host. Clearing the table does not fix an underlying VLAN misconfiguration and would result in the MAC being learned again in the wrong VLAN.
- B
Verify the VLAN assignment on Gi0/3 using 'show vlan brief' or 'show interfaces Gi0/3 switchport'.
The switch learns MAC addresses per VLAN. If Gi0/3 is in an unexpected VLAN, the MAC address will be learned in that VLAN's table and not visible in the default or expected VLAN view. Checking the VLAN membership directly confirms whether the host is in the correct Layer 2 broadcast domain.
- C
Check the STP state of Gi0/3 with 'show spanning-tree interface Gi0/3' to ensure it is not blocking.
Why wrong: Although a port in STP blocking state does not learn MAC addresses, an access port facing a single host normally transitions to forwarding quickly and is unlikely to be blocking after being connected for several minutes without a topology change. VLAN assignment should be verified first.
- D
Inspect the ARP cache with 'show ip arp' to check for duplicate IP addresses.
Why wrong: The ARP cache maps IP addresses to MAC addresses at Layer 3. The MAC address table is a Layer 2 function and will learn the host's MAC regardless of any IP addressing issues. A duplicate IP does not prevent MAC learning.
Quick Answer
The correct next step is to verify the VLAN assignment on Gi0/3 using show vlan brief or show interfaces Gi0/3 switchport. This is because the MAC address table is learned per VLAN, so if the port belongs to a different VLAN than the one the technician is checking, the host’s MAC will be recorded in that other VLAN and remain hidden from the expected output. Even with a physically up/up link and a recent connection, the switch will not populate the MAC address table for a VLAN that the port does not belong to, making VLAN misconfiguration the most common cause of a missing host MAC. On the CCNA 200-301 v2 exam, this scenario tests your understanding that Layer 2 forwarding is VLAN-specific, and the trap is to assume a cabling or duplex issue when the real problem is a mismatched broadcast domain. Remember the mnemonic: “MAC learns per VLAN, so check the plan.”
CCNA Switching and Network Access Practice Question
This 200-301 practice question tests your understanding of switching and network access. Examine the command output carefully: the correct answer depends on what the output actually shows, not on general recall alone. 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 host is physically connected to switch port Gi0/3. The technician runs 'show mac address-table' but does not find the host's MAC address for Gi0/3. The port status shows 'up/up', and the host was connected only a few minutes ago. What should the technician do next?
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
Verify the VLAN assignment on Gi0/3 using 'show vlan brief' or 'show interfaces Gi0/3 switchport'.
The MAC address table is learned per VLAN. If the port is assigned to a VLAN different from the one the technician expects, the host's MAC will be learned in that different VLAN and may not appear in the output shown. Checking the VLAN membership with 'show vlan' or 'show interfaces switchport' verifies the Layer 2 broadcast domain, which is the most likely reason the MAC is missing from the expected view.
Key principle: A trunk being up does not mean the VLAN is allowed across it. Always verify the allowed VLAN list and whether the VLAN exists on both switches.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Clear the MAC address table with 'clear mac address-table dynamic' to force immediate relearning.
Why it's wrong here
The default MAC aging time is 300 seconds, so aging is not the issue for a recently connected host. Clearing the table does not fix an underlying VLAN misconfiguration and would result in the MAC being learned again in the wrong VLAN.
- ✓
Verify the VLAN assignment on Gi0/3 using 'show vlan brief' or 'show interfaces Gi0/3 switchport'.
Why this is correct
The switch learns MAC addresses per VLAN. If Gi0/3 is in an unexpected VLAN, the MAC address will be learned in that VLAN's table and not visible in the default or expected VLAN view. Checking the VLAN membership directly confirms whether the host is in the correct Layer 2 broadcast domain.
Related concept
Access ports place end devices into a single VLAN.
- ✗
Check the STP state of Gi0/3 with 'show spanning-tree interface Gi0/3' to ensure it is not blocking.
Why it's wrong here
Although a port in STP blocking state does not learn MAC addresses, an access port facing a single host normally transitions to forwarding quickly and is unlikely to be blocking after being connected for several minutes without a topology change. VLAN assignment should be verified first.
- ✗
Inspect the ARP cache with 'show ip arp' to check for duplicate IP addresses.
Why it's wrong here
The ARP cache maps IP addresses to MAC addresses at Layer 3. The MAC address table is a Layer 2 function and will learn the host's MAC regardless of any IP addressing issues. A duplicate IP does not prevent MAC learning.
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.
✓Verify the VLAN assignment on Gi0/3 using 'show vlan brief' or 'show interfaces Gi0/3 switchport'.Correct answer▾
Why this is correct
The switch learns MAC addresses per VLAN. If Gi0/3 is in an unexpected VLAN, the MAC address will be learned in that VLAN's table and not visible in the default or expected VLAN view. Checking the VLAN membership directly confirms whether the host is in the correct Layer 2 broadcast domain.
✗Clear the MAC address table with 'clear mac address-table dynamic' to force immediate relearning.Wrong answer — click to see why▾
Why this is wrong here
This is a drastic action that does not address a VLAN mismatch; the same symptom would recur.
✗Check the STP state of Gi0/3 with 'show spanning-tree interface Gi0/3' to ensure it is not blocking.Wrong answer — click to see why▾
Why this is wrong here
Jumping to STP before confirming basic Layer 2 VLAN membership is not the most efficient next step.
✗Inspect the ARP cache with 'show ip arp' to check for duplicate IP addresses.Wrong answer — click to see why▾
Why this is wrong here
This option confuses Layer 2 MAC learning with Layer 3 ARP resolution, and does not help locate the MAC entry in the address table.
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?”
Common exam traps
Common exam trap: an active trunk can still block the VLAN you need
A trunk being up does not prove every VLAN is crossing it. Check allowed VLAN lists, native VLAN mismatch, VLAN existence and access-port assignment.
Detailed technical explanation
How to think about this question
VLAN questions usually combine access-port and trunking clues. The key is to identify whether the issue is local to one switchport, caused by the trunk, or caused by the VLAN not existing where it needs to exist.
KKey Concepts to Remember
- Access ports place end devices into a single VLAN.
- Trunk ports carry multiple VLANs between switches.
- Allowed VLAN lists decide which VLANs can cross a trunk.
- Native VLAN mismatch can create confusing symptoms.
TExam Day Tips
- Use show vlan brief to verify access VLANs.
- Use show interfaces trunk to verify trunk state and allowed VLANs.
- Do not treat every same-VLAN issue as a routing problem.
Key takeaway
A trunk being up does not mean the VLAN is allowed across it. Always verify the allowed VLAN list and whether the VLAN exists on both switches.
Real-world example
How this comes up in practice
A help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.
What to study next
Got this wrong? Here's your next step.
Review VLAN allowed lists, native VLAN mismatch detection, and how to verify VLAN membership with show vlan brief and show interfaces trunk. Then practise related 200-301 questions on switching, trunking, and access-port configuration.
- →
Switching and Network Access — study guide chapter
Learn the concepts, then practise the questions
- →
Switching and Network Access practice questions
Targeted practice on this topic area only
- →
All 200-301 questions
1,819 questions across all exam domains
- →
CCNA 200-301 v2 study guide
Full concept coverage aligned to exam objectives
- →
200-301 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network Infrastructure and Connectivity practice questions
Practise 200-301 questions linked to Network Infrastructure and Connectivity.
Switching and Network Access practice questions
Practise 200-301 questions linked to Switching and Network Access.
IP Routing practice questions
Practise 200-301 questions linked to IP Routing.
Network Services and Security practice questions
Practise 200-301 questions linked to Network Services and Security.
AI and Network Operations practice questions
Practise 200-301 questions linked to AI and Network Operations.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
Practice this exam
Start a free 200-301 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 200-301 question test?
Switching and Network Access — This question tests Switching and Network Access — Access ports place end devices into a single VLAN..
What is the correct answer to this question?
The correct answer is: Verify the VLAN assignment on Gi0/3 using 'show vlan brief' or 'show interfaces Gi0/3 switchport'. — The MAC address table is learned per VLAN. If the port is assigned to a VLAN different from the one the technician expects, the host's MAC will be learned in that different VLAN and may not appear in the output shown. Checking the VLAN membership with 'show vlan' or 'show interfaces switchport' verifies the Layer 2 broadcast domain, which is the most likely reason the MAC is missing from the expected view.
What should I do if I get this 200-301 question wrong?
Review VLAN allowed lists, native VLAN mismatch detection, and how to verify VLAN membership with show vlan brief and show interfaces trunk. Then practise related 200-301 questions on switching, trunking, and access-port configuration.
What is the key concept behind this question?
Access ports place end devices into a single VLAN.
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 →
Keep practising
More 200-301 practice questions
- A switchport connected to another switch should carry multiple VLANs, but it was manually configured as an access port.…
- What problem is HSRP designed to solve?
- Which TWO statements correctly describe the causes or implications of CRC errors, runts, giants, or output errors as see…
- You are connected to R1. Configure IPv4 and IPv6 addressing on R1's interfaces and verify reachability to R2. The curren…
- Which TWO statements accurately describe how AI/ML concepts are applied to network operations in modern enterprise netwo…
- Which TWO switch port configurations are required when connecting a Cisco IP phone and a desktop PC to a single access p…
Last reviewed: Jun 14, 2026
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.
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.