Question 518 of 1,819
Switching and Network AccesshardMultiple ChoiceObjective-mapped

CCNA Switching and Network Access Practice Question

This 200-301 practice question tests your understanding of switching and network access. 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 technician is troubleshooting an inter-VLAN routing issue on a multilayer switch. Hosts on VLAN 10 can reach the SVI for VLAN 10 (10.0.10.1) but cannot reach hosts on VLAN 20. The technician has verified that 'ip routing' is enabled and that the 'show ip route' command displays directly connected routes for both VLANs. No static routes are configured. What should the technician do next?

Question 1hardmultiple choice
Open the full VLAN trunking answer →

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

Check the ARP table for entries on VLAN 20.

Because the switch has directly connected routes for both VLANs and routing is enabled, the Layer 3 forwarding logic is intact. The failure from VLAN 10 hosts to VLAN 20 hosts suggests that the switch cannot resolve the destination host's MAC address on VLAN 20, preventing Layer 2 frame encapsulation. Checking the ARP table with 'show ip arp' or similar will reveal whether the destination IPv4 address has a valid MAC entry on the correct VLAN interface. This targets Layer 2—the most likely remaining failure point after Layer 3 has been verified.

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.

  • Check the ARP table for entries on VLAN 20.

    Why this is correct

    The Layer 3 routing table is correct; the problem is likely that the switch lacks a Layer 2 MAC address for the destination host on VLAN 20. Examining the ARP cache will confirm whether the switch can map the destination IP to a MAC address, and if not, will show that ARP resolution is failing, which explains the connectivity break.

    Related concept

    Access ports place end devices into a single VLAN.

  • Issue the 'show ip routing' command again to confirm routing is enabled.

    Why it's wrong here

    The technician has already verified that 'ip routing' is enabled and that the routing table contains the necessary connected routes. Repeating this check does not advance the troubleshooting process and ignores the likely Layer 2 issue.

  • Configure a default route pointing to the next-hop gateway.

    Why it's wrong here

    Both VLANs are directly connected networks on the multilayer switch; a default route is unnecessary for reaching locally attached subnets. Adding one would not resolve the problem and could even introduce routing issues.

  • Verify the VLAN membership of the destination host on VLAN 20.

    Why it's wrong here

    Although a mismatched VLAN could cause a connectivity problem, the scenario explicitly identifies the destination hosts as being on VLAN 20. The issue is between VLANs, not within a VLAN, and the Layer 3 information (connected route for VLAN 20) suggests the switch has an interface in that subnet. Checking ARP is more immediate and diagnostic than re-verifying VLAN assignment.

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.

Check the ARP table for entries on VLAN 20.Correct answer

Why this is correct

The Layer 3 routing table is correct; the problem is likely that the switch lacks a Layer 2 MAC address for the destination host on VLAN 20. Examining the ARP cache will confirm whether the switch can map the destination IP to a MAC address, and if not, will show that ARP resolution is failing, which explains the connectivity break.

Issue the 'show ip routing' command again to confirm routing is enabled.Wrong answer — click to see why

Why this is wrong here

This option revisits a step already completed and verified, making it redundant. Candidates might think double-checking routing is safe, but the scenario explicitly states routing is working as expected.

Configure a default route pointing to the next-hop gateway.Wrong answer — click to see why

Why this is wrong here

Some candidates might believe inter-VLAN communication requires a default route, but directly connected routes already provide full reachability without static routing. This action is overly drastic and misdirected.

Verify the VLAN membership of the destination host on VLAN 20.Wrong answer — click to see why

Why this is wrong here

Candidates often jump to VLAN misconfigurations when inter-VLAN communication fails, even when routing is confirmed. The scenario already establishes the VLAN 20 host's location; the next logical layer to inspect is ARP resolution.

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.

Trap categories for this question

  • Scenario analysis trap

    Although a mismatched VLAN could cause a connectivity problem, the scenario explicitly identifies the destination hosts as being on VLAN 20. The issue is between VLANs, not within a VLAN, and the Layer 3 information (connected route for VLAN 20) suggests the switch has an interface in that subnet. Checking ARP is more immediate and diagnostic than re-verifying VLAN 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.

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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: Check the ARP table for entries on VLAN 20. — Because the switch has directly connected routes for both VLANs and routing is enabled, the Layer 3 forwarding logic is intact. The failure from VLAN 10 hosts to VLAN 20 hosts suggests that the switch cannot resolve the destination host's MAC address on VLAN 20, preventing Layer 2 frame encapsulation. Checking the ARP table with 'show ip arp' or similar will reveal whether the destination IPv4 address has a valid MAC entry on the correct VLAN interface. This targets Layer 2—the most likely remaining failure point after Layer 3 has been verified.

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.

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Last reviewed: Jun 14, 2026

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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.