GSEC Networking and Protocols Practice Question
A help desk technician is troubleshooting a user's inability to reach an internal web application by its hostname, although the application is reachable by IP address. The user's workstation is configured with a DNS server address that is reachable. Which command should the technician run first to verify name resolution from the workstation?
⚠ Common exam trap
The trap here is reaching for a connectivity tool such as tracert or a configuration display like ipconfig /all, when the symptom specifically points to a name-resolution failure that only a DNS query can confirm.
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
✓
nslookup app.internal.example.com
Because the application is reachable by IP but not by hostname, the fault lies in name resolution rather than connectivity or routing. Querying DNS directly with nslookup tests whether the configured resolver returns the correct address or an error, which isolates the problem. Other commands either require successful resolution first or inspect unrelated local state.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
netstat -an
Why it's wrong here
netstat -an lists local sockets and their states; it shows whether the workstation has open connections but says nothing about DNS resolution. The user can already reach the application by IP, so socket state is not the failing component. Running netstat would not confirm whether the hostname resolves, making it a poor first diagnostic choice for this specific symptom.
- ✗
ipconfig /all
Why it's wrong here
ipconfig /all displays adapter configuration, including the configured DNS server addresses, but it does not perform a lookup. It can confirm that a DNS server is configured, yet it cannot tell the technician whether that server resolves the internal name. Since the scenario already states the DNS server address is reachable, this command adds little diagnostic value compared with an actual query.
- ✓
nslookup app.internal.example.com
Why this is correct
nslookup queries DNS servers directly and reports the resolved address or an error, which quickly confirms whether the configured resolver can resolve the internal hostname. Because the application works by IP, the failure is isolated to name resolution, and this command tests exactly that path. It is available on Windows, Linux, and macOS and is the appropriate first diagnostic step in this scenario.
- ✗
tracert app.internal.example.com
Why it's wrong here
tracert traces the Layer 3 path to a destination and requires the destination to be resolvable to an IP first. If name resolution is the problem, this command fails before it can produce useful path information, or it resolves the name using the same broken resolver. It does not isolate DNS from routing, so it is not the best first step here.
Visual reference
About these practice questions
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official GIAC exam blueprint
This GSEC practice question is part of Courseiva's free GIAC 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 GSEC exam.