LFCS Service Configuration Practice Question
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?
⚠ Common exam trap
Watch out — 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.
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
✓
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.
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.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This LFCS practice question is part of Courseiva's free Linux Foundation 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 LFCS exam.