This LFCS practice question tests your understanding of service configuration. 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.
Exhibit
● systemctl status sshd.service
● sshd.service - OpenSSH server daemon
Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Mon 2025-03-10 10:15:23 UTC; 2min ago
Docs: man:sshd(8)
man:sshd_config(5)
Process: 12345 ExecStart=/usr/sbin/sshd -D $OPTIONS (code=exited, status=255)
Main PID: 12345 (code=exited, status=255)
Status: "SSH Daemon exited abnormally"
Refer to the exhibit. What is the most likely cause of the sshd service failure?
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 sshd_config file is misconfigured.
The exhibit shows that the sshd service fails to start, and the most likely cause is a misconfiguration in the sshd_config file. When sshd is started via systemd, a syntax error or invalid directive in /etc/ssh/sshd_config will cause the daemon to exit immediately, resulting in a failed status. This is a common issue because sshd validates its configuration file at startup and will refuse to run if it finds an error.
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 OPTIONS environment variable is not set.
Why it's wrong here
Even if unset, sshd would start with defaults; it wouldn't cause exit 255.
✗
The service is not enabled to start at boot.
Why it's wrong here
The status shows 'enabled', so it is enabled.
✗
There is a syntax error in the unit file.
Why it's wrong here
The unit file loaded successfully, so no syntax error.
✓
The sshd_config file is misconfigured.
Why this is correct
sshd exiting with 255 often indicates bad configuration.
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.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often assume a unit file syntax error (Option C) is the cause, but systemd unit files are parsed before the service runs, so a unit file error would prevent the service from starting at all, whereas a misconfigured sshd_config allows the unit to start but causes the daemon to exit immediately after parsing the config.
Trap categories for this question
Command / output trap
The status shows 'enabled', so it is enabled.
Detailed technical explanation
How to think about this question
When sshd starts, it reads /etc/ssh/sshd_config and applies settings like port, authentication methods, and allowed users. A common misconfiguration is setting an invalid port number (e.g., outside 1-65535) or referencing a nonexistent authentication file, which causes sshd to exit with an error. Systemd captures the exit code and marks the service as failed, but the journal (via 'journalctl -u sshd') will show the specific sshd error, such as 'Bad configuration option' or 'fatal: Cannot bind to address'.
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 practitioner preparing for the LFCS exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Service Configuration — This question tests Service Configuration — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The sshd_config file is misconfigured. — The exhibit shows that the sshd service fails to start, and the most likely cause is a misconfiguration in the sshd_config file. When sshd is started via systemd, a syntax error or invalid directive in /etc/ssh/sshd_config will cause the daemon to exit immediately, resulting in a failed status. This is a common issue because sshd validates its configuration file at startup and will refuse to run if it finds an error.
What should I do if I get this LFCS 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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Question Discussion
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