- A
Check the DNS cache on the user's workstation
A corrupted or stale DNS cache can prevent a client from resolving a name even though the DNS server is functional. Flushing the cache often resolves the issue.
- B
Verify the default gateway configuration
Why wrong: Since the user can reach the server by IP address, the default gateway is working; the issue is name resolution, not routing.
- C
Renew the DHCP lease
Why wrong: Renewing the DHCP lease would reassign IP configuration but would not directly affect DNS resolution if the workstation already has correct DNS server addresses.
- D
Disable the Windows Firewall
Why wrong: Firewall rules at the client could block DNS traffic, but since other users can resolve the name and the client can reach the DNS server, this is less likely than a local DNS cache issue.
Quick Answer
The correct next step is to check the DNS cache on the user’s workstation. This is because the user can reach the server by IP address but not by domain name, while other workstations on the same subnet resolve the name without issue—a classic symptom of a stale DNS cache on the client. A corrupted or outdated cache entry can cause the local resolver to return an incorrect or nonexistent IP, preventing name resolution even when the DNS server itself is healthy. On the CompTIA Network+ N10-009 exam, this scenario tests your ability to isolate local versus network-wide issues; a common trap is jumping to firewall or server misconfiguration when the problem is client-side. Remember that flushing the cache with `ipconfig /flushdns` is the fastest fix for a stale entry. Memory tip: If the IP works but the name doesn’t, think “local cache attack”—the client’s own records are the culprit.
N10-009 Network Troubleshooting Practice Question
This N10-009 practice question tests your understanding of network troubleshooting. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: dNS cache stores recently resolved domain names and their IP addresses locally.. 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 user reports that they can access a web server by its IP address (e.g., 10.10.10.50) but cannot access it by its domain name (e.g., server.example.com). The technician verifies that the DNS server is reachable and that the name resolves correctly from other workstations on the same subnet. Which of the following should the technician check NEXT?
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 DNS cache on the user's workstation
The user's workstation can reach the web server by IP but not by domain name, while other workstations resolve the name correctly. This strongly suggests a local DNS resolution issue specific to that workstation, such as a corrupted or stale DNS cache. Flushing the DNS cache with `ipconfig /flushdns` is the logical next step before investigating broader network or firewall issues.
Key principle: DNS cache stores recently resolved domain names and their IP addresses locally.
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 DNS cache on the user's workstation
- ✗
Verify the default gateway configuration
Why it's wrong here
Since the user can reach the server by IP address, the default gateway is working; the issue is name resolution, not routing.
- ✗
Renew the DHCP lease
- ✗
Disable the Windows Firewall
Common exam traps
Common exam trap: answer the scenario, not the keyword
CompTIA often tests the distinction between connectivity issues (routing, firewall) and name resolution issues; the trap here is that candidates jump to checking the default gateway or firewall because they think 'can't reach the website,' but the symptom of IP working while domain fails points directly to the local DNS cache or resolver configuration.
Detailed technical explanation
How to think about this question
The DNS client on Windows caches both positive and negative responses (NXDOMAIN, SERVFAIL) to improve performance. A negative cache entry can persist for up to 900 seconds (default TTL for negative caching per RFC 2308). If the user's workstation previously received a failed DNS response for server.example.com, it will continue to fail until the cache is cleared or the TTL expires. The `ipconfig /displaydns` command can reveal such stale entries.
KKey Concepts to Remember
- DNS cache stores recently resolved domain names and their IP addresses locally.
- A stale or corrupted DNS cache can prevent correct name resolution.
- Flushing the DNS cache forces a client to perform new DNS queries.
- The `ipconfig /flushdns` command clears the DNS resolver cache on Windows.
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
DNS cache stores recently resolved domain names and their IP addresses locally.
Real-world example
How this comes up in practice
A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
What to study next
Got this wrong? Here's your next step.
Review dNS cache stores recently resolved domain names and their IP addresses locally., then practise related N10-009 questions on the same topic to reinforce the concept.
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FAQ
Questions learners often ask
What does this N10-009 question test?
Network Troubleshooting — This question tests Network Troubleshooting — DNS cache stores recently resolved domain names and their IP addresses locally..
What is the correct answer to this question?
The correct answer is: Check the DNS cache on the user's workstation — The user's workstation can reach the web server by IP but not by domain name, while other workstations resolve the name correctly. This strongly suggests a local DNS resolution issue specific to that workstation, such as a corrupted or stale DNS cache. Flushing the DNS cache with `ipconfig /flushdns` is the logical next step before investigating broader network or firewall issues.
What should I do if I get this N10-009 question wrong?
Review dNS cache stores recently resolved domain names and their IP addresses locally., then practise related N10-009 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
DNS cache stores recently resolved domain names and their IP addresses locally.
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Last reviewed: Jun 30, 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.
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