- A
Verify that the speed and duplex settings are set to auto-negotiation.
Why wrong: Checking speed/duplex is a layer-1/2 action, but it is not the immediate next step. Interface administrative status should be verified first because if the port is shut down, no speed or duplex negotiation occurs; this skips a more basic check.
- B
Check whether the SFP module type is incompatible with the switch.
Why wrong: While an incompatible SFP can cause a down/down state, the technician has just replaced the transceiver and should first rule out a simpler configuration issue like the port being administratively down before investigating hardware compatibility.
- C
Verify the VLAN assignment on the port.
Why wrong: A wrong VLAN assignment affects traffic forwarding at Layer 2 but does not cause a link to be down. The down/down state indicates a Layer 1 problem, so checking VLANs is irrelevant to restoring the link.
- D
Check the running configuration for the no shutdown command on the interface.
This is the most immediate and logical next step. A shut-down interface displays as down/down (or administratively down/down), and without verifying the administrative state, all other troubleshooting is premature. The technician has already addressed physical connectivity, so a configuration oversight must be ruled out.
CCNA Network Infrastructure and Connectivity Practice Question
This 200-301 practice question tests your understanding of network infrastructure and connectivity. 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 replaced a faulty SFP transceiver on a switch port. After replacement, the port remains in a down/down state. The technician verifies the fiber cable is securely connected at both ends and observes that the remote switch port is also in a down/down state. 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
Check the running configuration for the no shutdown command on the interface.
The correct answer is D because the most common cause of a port remaining in a down/down state after replacing a faulty SFP is that the interface is administratively down. The 'no shutdown' command must be applied to bring the interface up. Since the technician already verified physical connectivity and both ends show down/down, the issue is likely at the configuration layer, not the physical layer.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Verify that the speed and duplex settings are set to auto-negotiation.
Why it's wrong here
Checking speed/duplex is a layer-1/2 action, but it is not the immediate next step. Interface administrative status should be verified first because if the port is shut down, no speed or duplex negotiation occurs; this skips a more basic check.
- ✗
Check whether the SFP module type is incompatible with the switch.
Why it's wrong here
While an incompatible SFP can cause a down/down state, the technician has just replaced the transceiver and should first rule out a simpler configuration issue like the port being administratively down before investigating hardware compatibility.
- ✗
Verify the VLAN assignment on the port.
Why it's wrong here
A wrong VLAN assignment affects traffic forwarding at Layer 2 but does not cause a link to be down. The down/down state indicates a Layer 1 problem, so checking VLANs is irrelevant to restoring the link.
- ✓
Check the running configuration for the no shutdown command on the interface.
Why this is correct
This is the most immediate and logical next step. A shut-down interface displays as down/down (or administratively down/down), and without verifying the administrative state, all other troubleshooting is premature. The technician has already addressed physical connectivity, so a configuration oversight must be ruled out.
Related concept
Read the scenario before looking for a memorised answer.
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 running configuration for the no shutdown command on the interface.Correct answer▾
Why this is correct
This is the most immediate and logical next step. A shut-down interface displays as down/down (or administratively down/down), and without verifying the administrative state, all other troubleshooting is premature. The technician has already addressed physical connectivity, so a configuration oversight must be ruled out.
✗Verify that the speed and duplex settings are set to auto-negotiation.Wrong answer — click to see why▾
Why this is wrong here
Candidates assume a speed mismatch must be the problem due to the down/down state, overlooking that a shutdown interface also appears down/down (without the 'administratively' prefix in some outputs) and that the physical check was already done.
✗Check whether the SFP module type is incompatible with the switch.Wrong answer — click to see why▾
Why this is wrong here
The urgency to blame the newly installed hardware leads many to skip the quick-win config check, potentially wasting time on hardware replacement when the fix is a single command.
✗Verify the VLAN assignment on the port.Wrong answer — click to see why▾
Why this is wrong here
Candidates often confuse link status with connectivity issues that occur after the link is up, mistakenly targeting a Layer 2 problem for a Layer 1 symptom.
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: answer the scenario, not the keyword
Cisco often tests the distinction between physical layer issues (cable, SFP) and administrative state issues (shutdown), where candidates mistakenly focus on hardware compatibility or VLAN settings when the port is simply disabled via configuration.
Detailed technical explanation
How to think about this question
The 'show interfaces status' command displays the administrative and operational status of a port. A down/down state means the interface is administratively down (shutdown) and the line protocol is also down. After replacing hardware, the interface may remain in shutdown if it was previously disabled or if the configuration was not saved. The 'no shutdown' command is required to enable the interface at Layer 1, and it must be applied in interface configuration mode. In real-world scenarios, technicians often forget to re-enable the port after a hardware swap, especially if the original SFP failure caused the port to be manually shut down.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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
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FAQ
Questions learners often ask
What does this 200-301 question test?
Network Infrastructure and Connectivity — This question tests Network Infrastructure and Connectivity — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Check the running configuration for the no shutdown command on the interface. — The correct answer is D because the most common cause of a port remaining in a down/down state after replacing a faulty SFP is that the interface is administratively down. The 'no shutdown' command must be applied to bring the interface up. Since the technician already verified physical connectivity and both ends show down/down, the issue is likely at the configuration layer, not the physical layer.
What should I do if I get this 200-301 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 25, 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.
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