SK0-005 troubleshooting Practice Question
A server uses NIC teaming with LACP (802.3ad) for load balancing and failover. After replacing a failed switch with a new switch of the same model, the server loses network connectivity. The switch ports show no activity. Which of the following is the MOST likely cause?
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
✓
LACP is not enabled on the switch ports.
LACP must be explicitly enabled and configured on switch ports to form a port-channel (Option D). New switches ship with default configurations that do not include LACP. The server's NIC teaming mode (Option A) was previously working, so it is likely correct. Access port configuration (Option B) would affect VLAN membership but not completely drop traffic. Firmware differences (Option C) rarely cause total loss of connectivity without other configuration mismatches.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The switch ports are not configured as access ports.
Why it's wrong here
If required, this could cause VLAN issues but would not usually result in zero activity on ports.
- ✗
The new switch has a different firmware version.
Why it's wrong here
Firmware differences alone are unlikely to cause complete lack of connectivity if the configuration is identical.
- ✗
The server's NIC teaming mode is set to active/passive.
Why it's wrong here
If it was working with the previous switch, the mode is compatible; active/passive would at least have one active link.
- ✓
LACP is not enabled on the switch ports.
Why this is correct
LACP requires configuration on the switch; default is no LACP, so the switch does not negotiate the port-channel, leading to no connectivity.
Visual reference
Go deeper
Related to this question
Learn chapter
Network Configuration and Connectivity
Key term
Firmware
Firmware is specialized software permanently stored in read-only memory on a hardware device that controls how that device operates at a basic level.
Key term
VLAN
A VLAN (Virtual Local Area Network) is a logical grouping of network devices that behave as if they are on the same physical network segment, regardless of their actual physical location.
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This SK0-005 question is part of Courseiva's 185-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on SK0-005
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A server has two NICs configured in a team using LACP. The server loses network connectivity when one NIC is physically disconnected, even though both links show as active in the teaming software before the failure. What is the most likely cause of the issue?
hard- ✓ A.LACP is not correctly configured on the switch
- B.The teaming mode is set to 'Switch Independent' instead of LACP
- C.Spanning Tree Protocol is blocking the failover path
- D.NIC driver version mismatch between the two adapters
Why A: For LACP to work properly, the switch must be explicitly configured to bundle the ports into a port channel. If the switch is not configured for LACP, it may not handle the failover correctly, causing a loss of connectivity when one link drops. NIC driver issues or STP are less likely to cause this specific symptom, and setting the team to Switch Independent would not use LACP.
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed July 2026 · checked against the official CompTIA exam blueprint
This SK0-005 practice question is part of Courseiva's free CompTIA 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 SK0-005 exam.