The answer is a missing default gateway on the new switch. When a switch is configured with a management IP address in one subnet, such as 10.1.2.50/24, and a management station resides in a different subnet like 10.1.1.0/24, the switch can receive incoming pings but cannot send a reply back unless it knows where to route the return traffic. Without a default gateway, the switch assumes all destinations are local, so it drops any response destined for a non-local address, making it unreachable from the remote subnet. On the CompTIA Network+ N10-009 exam, this scenario tests your understanding of Layer 3 forwarding for management traffic—a common trap is assuming routing on the distribution switch alone is sufficient, when the end device itself must also have a gateway. A useful memory tip: “A switch without a gateway is a local-only hermit—it can listen but never reply across subnets.”
N10-009 Network Implementation Practice Question
This N10-009 practice question tests your understanding of network implementation. 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 new switch is installed in a remote wiring closet. It has been configured with a management IP address of 10.1.2.50/24. The switch is connected via a trunk to the distribution switch, and the management station (10.1.1.0/24) is on a different subnet. The switch cannot be pinged from the management station. The distribution switch has routing to the 10.1.2.0/24 subnet. 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 default gateway is not configured on the new switch.
The management station is on subnet 10.1.1.0/24, while the switch's management IP is 10.1.2.50/24. For the switch to reply to pings from a different subnet, it must have a default gateway configured so it knows where to send return traffic. Without a default gateway, the switch will only respond to traffic on its local subnet, making it unreachable from the management station.
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.
✗
The management VLAN is not allowed on the trunk.
Why it's wrong here
If the management VLAN were not allowed, the switch would not be reachable from its own VLAN either.
✓
The default gateway is not configured on the new switch.
Why this is correct
The switch must have a default gateway pointing to the distribution switch to route responses to other subnets.
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 switch port to the distribution switch is in access mode.
Why it's wrong here
Access mode would prevent trunking, causing loss of connectivity entirely, not just cross-subnet.
✗
The management IP is configured on the wrong VLAN.
Why it's wrong here
While possible, the more likely and common oversight is the missing default gateway.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that a management IP alone is sufficient for remote access, but candidates forget that a default gateway is mandatory for inter-subnet communication, especially when the management station and switch are on different subnets.
Detailed technical explanation
How to think about this question
When a switch is configured with an IP address on a VLAN interface (SVI), it behaves like a host on that subnet. For traffic destined to a different subnet, the switch must send packets to a router; this is accomplished by configuring the 'ip default-gateway' command (for Layer 2 switches) or 'ip route 0.0.0.0 0.0.0.0 <next-hop>' (for Layer 3 switches). Without this, the switch will drop any packets with a destination IP outside its own subnet, as it has no routing table entry for remote networks.
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this N10-009 question in full detail.
Network Implementation — This question tests Network Implementation — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The default gateway is not configured on the new switch. — The management station is on subnet 10.1.1.0/24, while the switch's management IP is 10.1.2.50/24. For the switch to reply to pings from a different subnet, it must have a default gateway configured so it knows where to send return traffic. Without a default gateway, the switch will only respond to traffic on its local subnet, making it unreachable from the management station.
What should I do if I get this N10-009 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.
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