The answer is a default gateway misconfiguration, specifically when the VM is using a different default gateway than the VMkernel interface. This is correct because the VM can send traffic out successfully—indicating Layer 2 connectivity and VLAN tagging are fine—but cannot receive return traffic from external networks, which points to a routing asymmetry. When the VM’s default gateway does not match the subnet’s actual gateway, the VMkernel interface may intercept or misroute inbound packets, breaking the return path. On the VMware Certified Professional Data Center Virtualization VCP-DCV exam, this scenario tests your ability to distinguish between switching issues (like VLAN mismatches) and routing problems; a common trap is to blame the port group or physical switch when the real culprit is the VM’s IP configuration. Remember: outbound traffic only needs a route, but inbound traffic needs the correct gateway to find its way back. Memory tip: “Outbound OK, inbound stuck? Check the gateway—it’s likely a routing truck.”
VCP-DCV Configure and Manage vSphere Networking Practice Question
This VCP-DCV practice question tests your understanding of configure and manage vsphere networking. 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 VM on a vSphere Distributed Switch is unable to receive traffic from external networks. The VM can send traffic out successfully. The VM port group has no security policies set (default). The physical switch port is configured as an access port on VLAN 100. The VM port group VLAN is set to 100. What is the most likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The VM is using a different default gateway than the VMkernel interface
Option C is correct because the VM can send traffic out successfully but cannot receive traffic from external networks, which indicates a routing issue rather than a switching or VLAN problem. The most likely cause is that the VM's default gateway is set to the VMkernel interface's IP address instead of the physical network's gateway, causing return traffic to be misrouted. This is a common misconfiguration where the VM's default gateway does not match the subnet's gateway, preventing inbound traffic from reaching the VM.
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.
✗
VLAN mismatch between VM port group and physical switch
Why it's wrong here
VLANs match.
✗
The VM's NIC is in promiscuous mode
Why it's wrong here
Promiscuous mode would not prevent incoming traffic.
✓
The VM is using a different default gateway than the VMkernel interface
Why this is correct
Asymmetric routing can cause one-way traffic.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
The physical switch port is configured as an access port instead of a trunk
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often focus on VLAN configuration or switch port modes when the symptom is unidirectional traffic, but the real issue is a routing misconfiguration at the VM's default gateway, which is a common oversight in vSphere networking troubleshooting.
Detailed technical explanation
How to think about this question
When a VM sends traffic out, the source IP is its own, and the destination IP is the external host; the VM's default gateway is used to route the packet to the next hop. For inbound traffic, the external host must send packets to the VM's IP, and the network's routing table must have a route back to the VM's subnet; if the VM's default gateway is set to the VMkernel interface (which is on a different subnet or a management network), the return traffic may be sent to the wrong gateway or dropped. This scenario often occurs in nested virtualization or when the VM is configured with a static IP and the default gateway is accidentally pointed to the ESXi host's management IP instead of the physical router's IP.
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
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Configure and Manage vSphere Networking — This question tests Configure and Manage vSphere Networking — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The VM is using a different default gateway than the VMkernel interface — Option C is correct because the VM can send traffic out successfully but cannot receive traffic from external networks, which indicates a routing issue rather than a switching or VLAN problem. The most likely cause is that the VM's default gateway is set to the VMkernel interface's IP address instead of the physical network's gateway, causing return traffic to be misrouted. This is a common misconfiguration where the VM's default gateway does not match the subnet's gateway, preventing inbound traffic from reaching the VM.
What should I do if I get this VCP-DCV question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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 →
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.
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.
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.
Sign in to join the discussion.