Question 723 of 1,819
Switching and Network AccesshardTroubleshootingObjective-mapped

CCNA Switching and Network Access Practice Question

This 200-301 practice question tests your understanding of switching and network access. 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.

Network Topology
G0/0G0/0G0/1G0/0G0/2G0/0G0/3SW1SW2SW3SW4Server

You are connected to SW1. The network has experienced a spanning-tree topology change, and the new root bridge is not the intended core switch. Configure SW1 with a root primary priority, enable PortFast and BPDU Guard on interface GigabitEthernet0/3 (an edge port connected to a server), and verify that a specific port in the topology is blocking. Then, after a BPDU violation occurs on G0/3, recover the interface from err-disable state without reloading the switch.

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "primary"

    Why it matters: Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.

Question 1hardTroubleshooting
Full question →

Exhibit

SW1# show spanning-tree
  VLAN0001
    Spanning tree enabled protocol rstp
    Root ID    Priority    32769
               Address     0001.1111.1111
               This bridge is the root
               Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec

    Bridge ID  Priority    32769  (priority 32768 sys-id-ext 1)
               Address     0001.2222.2222
               Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
               Aging Time  300 sec

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0               Desg FWD 4         128.1    P2p
Gi0/1               Desg FWD 4         128.2    P2p
Gi0/2               Desg FWD 4         128.3    P2p
Gi0/3               Desg FWD 4         128.4    P2p Edge


SW1# show running-config interface GigabitEthernet0/3
Building configuration...

Current configuration : 60 bytes
!
interface GigabitEthernet0/3
 switchport mode access
end


SW1# show interfaces status err-disabled
Port         Name               Status       Reason
Gi0/3                           err-disabled bpduguard

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

spanning-tree vlan 1 root primary; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpduguard enable; interface GigabitEthernet0/3; shutdown; no shutdown

The current root bridge has priority 32769, but the intended root should be SW1 with a lower priority. First, configure SW1 as root primary using 'spanning-tree vlan 1 root primary' or manually set priority to 24576. For edge port Gi0/3, enable PortFast with 'spanning-tree portfast' and BPDU Guard with 'spanning-tree bpduguard enable'. After the BPDU violation, the port is err-disabled. To recover, first shut down and then no shut the interface, or use 'errdisable recovery cause bpduguard' and wait for the recovery interval, but the most direct method is to manually bounce the interface.

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.

  • spanning-tree vlan 1 root primary; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpduguard enable; interface GigabitEthernet0/3; shutdown; no shutdown

    Why this is correct

    This sequence correctly configures SW1 as root primary for VLAN 1, enables PortFast and BPDU Guard on the edge port, and recovers the err-disabled interface by manually bouncing it (shutdown/no shutdown).

    Clue confirmation

    The clue word "primary" in the question point toward this answer.

    Related concept

    Access ports place end devices into a single VLAN.

  • spanning-tree vlan 1 priority 4096; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpduguard enable; interface GigabitEthernet0/3; errdisable recovery cause bpduguard

    Why it's wrong here

    This is incorrect because setting priority to 4096 is not the standard root primary method; the root primary command sets priority to 24576 or lower. Also, errdisable recovery cause bpduguard only enables automatic recovery after a timer, not immediate recovery.

  • spanning-tree vlan 1 root secondary; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpduguard enable; interface GigabitEthernet0/3; no shutdown

    Why it's wrong here

    This is incorrect because 'root secondary' sets the switch to be a backup root (priority 28672), not the primary root. Also, 'no shutdown' alone does not recover an err-disabled port; you must first shut it down.

  • spanning-tree vlan 1 root primary; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpdufilter enable; interface GigabitEthernet0/3; shutdown; no shutdown

    Why it's wrong here

    This is incorrect because BPDU filter (bpdufilter) is used to prevent sending/receiving BPDUs on a port, not to protect against BPDU violations. BPDU Guard is the correct feature to err-disable a port upon receiving a BPDU.

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.

spanning-tree vlan 1 root primary; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpduguard enable; interface GigabitEthernet0/3; shutdown; no shutdownCorrect answer

Why this is correct

This sequence correctly configures SW1 as root primary for VLAN 1, enables PortFast and BPDU Guard on the edge port, and recovers the err-disabled interface by manually bouncing it (shutdown/no shutdown).

spanning-tree vlan 1 priority 4096; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpduguard enable; interface GigabitEthernet0/3; errdisable recovery cause bpduguardWrong answer — click to see why

Why this is wrong here

The priority value 4096 is not used by the root primary command; it sets priority to 24576. Additionally, errdisable recovery does not immediately recover the port; it requires a timer.

Why candidates choose this

Candidates may think any low priority works and that errdisable recovery is the only way to recover, but manual shutdown/no shutdown is faster and more direct.

spanning-tree vlan 1 root secondary; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpduguard enable; interface GigabitEthernet0/3; no shutdownWrong answer — click to see why

Why this is wrong here

Root secondary makes the switch a secondary root, not primary. An err-disabled port requires a shutdown before no shutdown to clear the error state.

Why candidates choose this

Candidates might confuse root secondary with root primary, and think no shutdown alone can recover an err-disabled port, but the port must be cycled.

spanning-tree vlan 1 root primary; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpdufilter enable; interface GigabitEthernet0/3; shutdown; no shutdownWrong answer — click to see why

Why this is wrong here

BPDU filter does not trigger err-disable on BPDU reception; it silently drops BPDUs. BPDU Guard is needed to protect edge ports.

Why candidates choose this

Candidates may confuse BPDU filter with BPDU Guard, as both are related to BPDU handling on PortFast ports, but they serve different purposes.

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

  • Command / output trap

    This is incorrect because setting priority to 4096 is not the standard root primary method; the root primary command sets priority to 24576 or lower. Also, errdisable recovery cause bpduguard only enables automatic recovery after a timer, not immediate recovery.

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.

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.

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: spanning-tree vlan 1 root primary; interface GigabitEthernet0/3; spanning-tree portfast; spanning-tree bpduguard enable; interface GigabitEthernet0/3; shutdown; no shutdown — The current root bridge has priority 32769, but the intended root should be SW1 with a lower priority. First, configure SW1 as root primary using 'spanning-tree vlan 1 root primary' or manually set priority to 24576. For edge port Gi0/3, enable PortFast with 'spanning-tree portfast' and BPDU Guard with 'spanning-tree bpduguard enable'. After the BPDU violation, the port is err-disabled. To recover, first shut down and then no shut the interface, or use 'errdisable recovery cause bpduguard' and wait for the recovery interval, but the most direct method is to manually bounce the interface.

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.

Are there clue words in this question I should notice?

Yes — watch for: "primary". Asks for the main purpose or function, not a secondary benefit. Eliminate answers that describe side-effects or partial functions.

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 →

How Courseiva writes practice questions · Editorial policy

Last reviewed: Jun 6, 2026

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.

Loading comments…

Sign in to join the discussion.

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.