Question 150 of 464
N10-009 Network Troubleshooting Practice Question
A user can ping the default gateway (192.168.1.1) but cannot access the internet (e.g., ping 8.8.8.8 fails). The user's IP is correctly configured as 192.168.1.10/24. What should the technician check next?
⚠ Common exam trap
The N10-009 exam often tests the distinction between local connectivity (pinging the gateway) and external connectivity (pinging a public IP), where candidates mistakenly jump to DNS or subnet mask issues instead of recognizing the router's lack of a default route as the root 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
✓
Check the router's default route configuration
Since the user can ping the default gateway (192.168.1.1), Layer 2 and Layer 3 connectivity within the local subnet is working, and the PC's IP configuration is correct. The failure to reach 8.8.8.8 indicates that the router does not have a valid path to external networks, which is typically provided by a default route (0.0.0.0/0). Checking the router's default route configuration is the logical next step because without it, the router cannot forward traffic destined for non-local networks.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Check the PC's DNS server settings
Why it's wrong here
Checking the PC's DNS server settings is irrelevant to the problem described because the user can successfully ping an IP address (the default gateway). DNS is responsible for resolving hostnames to IP addresses, not for establishing fundamental IP connectivity. If the issue were solely DNS, the user would still be able to ping external IP addresses directly, even if hostname resolution failed, which is not the implied scenario here.
When this WOULD be correct
A user can ping the gateway and external IPs (e.g., 8.8.8.8) but cannot browse websites by name (e.g., www.google.com). In that scenario, DNS server settings would be the correct next check.
- ✗
Verify the subnet mask on the PC
Why it's wrong here
The successful ping to the default gateway (192.168.1.1) from the PC indicates that the PC's IP address and subnet mask are correctly configured for local network communication. An incorrect subnet mask would prevent the PC from recognizing its own local network and, therefore, it would be unable to communicate with its default gateway in the first place, making this an unlikely cause for the observed symptoms.
When this WOULD be correct
A user cannot ping any device on the local network, including the default gateway, despite having a valid IP address. The technician should verify the subnet mask to ensure it matches the network's subnet.
- ✓
Check the router's default route configuration
Why this is correct
The ability to ping the default gateway confirms local network connectivity between the PC and the router. However, if the router lacks a configured default route (0.0.0.0/0), it will not know where to forward packets destined for networks beyond its directly connected interfaces, such as the internet. Consequently, all traffic intended for external destinations would be dropped by the router, preventing the user from reaching anything outside the local subnet.
- ✗
Examine the switch port VLAN assignment
Why it's wrong here
The fact that the user can successfully ping the default gateway confirms that the PC is correctly assigned to the appropriate VLAN on the switch port. If the switch port's VLAN assignment were incorrect, the PC would be isolated from its default gateway, preventing any Layer 2 or Layer 3 communication with it. Therefore, the VLAN configuration is not the source of the problem.
When this WOULD be correct
This option would be correct if the user could not ping the default gateway or any other device on the same subnet, suggesting a Layer 2 problem. For example, a question where a user with a static IP cannot communicate with any local host, and the switch port is in the wrong VLAN.
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 N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓Check the router's default route configurationCorrect answer▾
Why this is correct
The ability to ping the default gateway confirms local network connectivity between the PC and the router. However, if the router lacks a configured default route (0.0.0.0/0), it will not know where to forward packets destined for networks beyond its directly connected interfaces, such as the internet. Consequently, all traffic intended for external destinations would be dropped by the router, preventing the user from reaching anything outside the local subnet.
✗Check the PC's DNS server settingsWrong answer — click to see why▾
Why this is wrong here
The user can ping the default gateway, indicating Layer 3 connectivity to the router, but cannot reach the internet. This points to a routing issue beyond the local subnet, not DNS, since ping uses IP addresses, not hostnames.
★ When this WOULD be the correct answer
A user can ping the gateway and external IPs (e.g., 8.8.8.8) but cannot browse websites by name (e.g., www.google.com). In that scenario, DNS server settings would be the correct next check.
Why candidates choose this
Candidates often associate internet access problems with DNS, but the question specifies ping to an IP address fails, which bypasses DNS, making this a red herring.
✗Verify the subnet mask on the PCWrong answer — click to see why▾
Why this is wrong here
The user can ping the default gateway, indicating that the subnet mask is correctly configured for local network communication. A subnet mask issue would prevent pinging the gateway, so it is not the next step.
★ When this WOULD be the correct answer
A user cannot ping any device on the local network, including the default gateway, despite having a valid IP address. The technician should verify the subnet mask to ensure it matches the network's subnet.
Why candidates choose this
Candidates may think that internet access failure is often due to misconfigured subnet masks, but since the gateway is reachable, the subnet mask is likely correct.
✗Examine the switch port VLAN assignmentWrong answer — click to see why▾
Why this is wrong here
The user can ping the default gateway, indicating Layer 2 and Layer 3 connectivity within the local subnet. A switch port VLAN misconfiguration would typically prevent communication with the default gateway, so it is not the issue here.
★ When this WOULD be the correct answer
This option would be correct if the user could not ping the default gateway or any other device on the same subnet, suggesting a Layer 2 problem. For example, a question where a user with a static IP cannot communicate with any local host, and the switch port is in the wrong VLAN.
Why candidates choose this
Candidates may confuse symptoms of VLAN misconfiguration (no connectivity to gateway) with internet access issues, or they may think VLANs affect routing beyond the local network.
Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Visual reference
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 →
Last reviewed: Jun 11, 2026
This N10-009 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 N10-009 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.