N10-009 Network Troubleshooting Practice Question
A user reports that they can access the company's internal web server by IP address (10.10.10.100) but cannot access it by its hostname (intranet.company.com). The user's workstation is configured with the correct internal DNS server address. Which of the following should the technician do FIRST?
⚠ Common exam trap
The N10-009 exam often tests the distinction between connectivity issues (firewall, routing) and name resolution issues; the trap here is that candidates might jump to flushing the DNS cache (Option C) without verifying the authoritative DNS record first.
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 server's A record for intranet.company.com
The user can reach the server by IP but not by hostname, which indicates a DNS resolution problem. Since the workstation is configured with the correct internal DNS server, the most likely cause is a missing or incorrect A record for intranet.company.com on that DNS server. Checking the A record is the logical first step before other troubleshooting.
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 server's A record for intranet.company.com
Why this is correct
The ability to access the server by its IP address confirms network connectivity and the server's operational status. However, the inability to reach it by its hostname, intranet.company.com, directly points to a name resolution issue. An A (Address) record on the DNS server maps a hostname to its corresponding IPv4 address. If this specific A record is missing, incorrect, or misconfigured on the internal DNS server, clients will fail to resolve the hostname to the correct IP, even if the server is otherwise accessible.
- ✗
Review the firewall rules on the server
Why it's wrong here
Firewall rules primarily govern network traffic flow by permitting or denying connections based on IP addresses, ports, and protocols. Since the user can successfully access the internal web server using its IP address, it indicates that the server's firewall is not blocking the necessary web traffic (e.g., HTTP/HTTPS) to the server itself. Firewall rules do not interfere with the process of translating a hostname into an IP address, which is handled by DNS.
When this WOULD be correct
A technician should review firewall rules on the server when a user cannot access the server by either IP or hostname, and other connectivity checks (like ping) fail, indicating a possible firewall block.
- ✗
Run ipconfig /flushdns on the workstation
Why it's wrong here
Running ipconfig /flushdns clears the local DNS resolver cache on the workstation, which can resolve issues caused by stale or incorrect cached DNS entries. While a useful troubleshooting step for individual client-side resolution problems, it would not address a fundamental issue where the authoritative DNS server itself lacks or has an incorrect A record for intranet.company.com. If the server providing the DNS information is faulty, flushing the client's cache will only lead to re-querying the same incorrect information.
When this WOULD be correct
A user reports that after changing the IP address of a server, they still get the old IP when pinging the hostname. Running ipconfig /flushdns would clear the cached negative or outdated entry, forcing a fresh DNS query.
- ✗
Verify the default gateway configuration
Why it's wrong here
The default gateway is essential for routing network traffic from a local subnet to devices on different subnets or the internet. Since the user can successfully access the internal web server by its IP address, it confirms that the workstation's network connectivity and routing, including the default gateway configuration, are functioning correctly. A misconfigured default gateway would prevent any communication with the server, whether by IP or hostname, if the server is not on the local subnet.
When this WOULD be correct
A user cannot access any external websites or internal servers by IP address, and the workstation has a static IP configuration. In that scenario, verifying the default gateway would be the first step to ensure the workstation can route traffic outside its subnet.
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 DNS server's A record for intranet.company.comCorrect answer▾
Why this is correct
The ability to access the server by its IP address confirms network connectivity and the server's operational status. However, the inability to reach it by its hostname, intranet.company.com, directly points to a name resolution issue. An A (Address) record on the DNS server maps a hostname to its corresponding IPv4 address. If this specific A record is missing, incorrect, or misconfigured on the internal DNS server, clients will fail to resolve the hostname to the correct IP, even if the server is otherwise accessible.
✗Review the firewall rules on the serverWrong answer — click to see why▾
Why this is wrong here
The user can already access the server by IP, so connectivity and firewall rules are not the issue. The problem is specifically with hostname resolution, not network access.
★ When this WOULD be the correct answer
A technician should review firewall rules on the server when a user cannot access the server by either IP or hostname, and other connectivity checks (like ping) fail, indicating a possible firewall block.
Why candidates choose this
Candidates may assume that name resolution failures are often caused by firewall rules blocking DNS traffic, but here the workstation can resolve other names (implied) and the DNS server address is correct, so the issue is likely a missing A record.
✗Run ipconfig /flushdns on the workstationWrong answer — click to see why▾
Why this is wrong here
The user can access the server by IP but not by hostname, indicating a DNS resolution issue. Flushing the DNS cache would not fix a missing or incorrect A record on the DNS server.
★ When this WOULD be the correct answer
A user reports that after changing the IP address of a server, they still get the old IP when pinging the hostname. Running ipconfig /flushdns would clear the cached negative or outdated entry, forcing a fresh DNS query.
Why candidates choose this
Candidates often think that DNS issues are always client-side cache problems, so they jump to flushing DNS without considering that the server-side record might be missing or wrong.
✗Verify the default gateway configurationWrong answer — click to see why▾
Why this is wrong here
The user can access the internal web server by IP but not by hostname, indicating a DNS resolution issue, not a routing problem. The default gateway is only relevant for reaching external networks, not for internal hostname resolution.
★ When this WOULD be the correct answer
A user cannot access any external websites or internal servers by IP address, and the workstation has a static IP configuration. In that scenario, verifying the default gateway would be the first step to ensure the workstation can route traffic outside its subnet.
Why candidates choose this
Candidates may confuse connectivity issues with DNS problems, thinking that if the hostname doesn't work, the default gateway might be misconfigured, even though IP access works fine.
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
Quick reference
Common DNS Record Types
| Record | Purpose | Example |
|---|---|---|
| A | IPv4 address mapping | example.com → 93.184.216.34 |
| AAAA | IPv6 address mapping | example.com → 2606:2800::1 |
| CNAME | Alias to another hostname | www → example.com |
| MX | Mail server for domain | example.com → mail.example.com (priority 10) |
| TXT | Text data (SPF, DKIM, verification) | v=spf1 include:_spf.example.com ~all |
| NS | Authoritative name servers | example.com NS ns1.example.com |
| PTR | Reverse DNS (IP → hostname) | 34.216.184.93.in-addr.arpa → example.com |
| SOA | Zone authority record | Primary NS, admin email, serial, TTL defaults |
Go deeper
Related to this question
Learn chapter
Troubleshooting Methodology
Key term
A record
An A record is a type of DNS resource record that maps a domain name to an IPv4 address.
Key term
CAN
A CAN (Controller Area Network) is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other without a host computer.
About these practice questions
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.