Down Uplink Troubleshooting
A vSphere administrator notices that VMs on a specific ESXi host lose connectivity intermittently. The VMs are on a distributed switch port group. The administrator finds that the Uplink 1 on that host is down. What should the administrator do first?
Quick Answer
Checking the physical switch port configuration for the failed uplink is the right first step because troubleshooting should start at the most direct, most likely point of failure before making any changes to the virtual environment. An uplink reported down almost always has a physical-layer or physical-switch-side explanation, such as a disabled port, a misapplied VLAN or trunk setting, a bad cable, or a failed transceiver, and none of the virtual-switch-side fixes can actually resolve a link that is down for a physical reason. Options like adding more uplinks, changing the load-balancing algorithm, or reordering failover priority might reduce the symptom of intermittent connectivity by relying more heavily on the remaining working uplinks, but they leave the actual failed link unaddressed and do not explain why it went down in the first place. Diagnosing before reconfiguring is the more disciplined approach: understanding the physical switch port's state tells you whether this is a simple fix, like re-enabling a disabled port, or something requiring a hardware replacement or vendor escalation. Only once the true cause is understood does it make sense to consider whether any teaming or failover adjustments are also warranted as extra resilience going forward. Whenever a scenario reports a downed uplink and asks for the first troubleshooting step, favor diagnosing the physical connection and switch configuration over any virtual-switch workaround that merely routes around the failure.
⚠ Common exam trap
VCP-DCV often tests whether candidates jump to vSphere-level remediation (teaming, failover order) instead of first checking the physical network layer, which is the actual root cause in most uplink-down scenarios.
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 physical switch port configuration for the failed uplink
When an uplink is down on a host attached to a distributed switch, the first step is to verify the physical layer — the physical switch port, cable, and SFP — because the most common cause is a physical link failure or misconfiguration on the upstream switch. Only after confirming the physical layer should you adjust vSphere teaming or failover settings.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Increase the number of uplinks in the teaming policy
Why it's wrong here
Adding uplinks does not restore the failed physical link or move traffic onto Uplink 2, so intermittent VM connectivity persists. It is tempting because more uplinks increase aggregate bandwidth and redundancy, which is valid capacity planning, but the immediate fault is a single down uplink needing failover, not insufficient uplink count.
- ✓
Check the physical switch port configuration for the failed uplink
Why this is correct
A down uplink usually stems from the physical layer, so verify the connected switch port's configuration, VLAN trunking and status before touching vSphere settings. This identifies whether the fault lies with the physical switch or cabling.
- ✗
Set the load balancing policy to Route based on source MAC
Why it's wrong here
Source MAC load balancing still hashes traffic across the team including the failed Uplink 1, so some VM traffic is blackholed. It is tempting because changing the teaming policy is a legitimate tuning step, but Route based on source MAC suits stable per-VM path selection, not recovering from a downed uplink.
- ✗
Configure a different failover order
Why it's wrong here
Changing failover order alters which uplink is used after a failure, but Uplink 1 being down means the physical link or its upstream switch port needs restoring first. Failover order is tempting because it governs redundancy, yet it cannot fix a dead link that must be brought back up.
Go deeper
Related to this question
About these practice questions
One of 281 original VCP-DCV practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on VCP-DCV
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. Refer to the exhibit. An administrator notices that two uplinks are down on the VDS. Which step should be taken first to restore redundancy?
hard- ✓ A.Check the physical switch ports and cables for uplink2 and uplink3.
- B.Increase the MTU to 9000 to improve performance.
- C.Disable LACP on the VDS to allow single-uplink operation.
- D.Remove the down uplinks from the VDS.
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official VMware exam blueprint
This VCP-DCV practice question is part of Courseiva's free VMware 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 VCP-DCV exam.