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XK0-006 Practice Question: Based on the exhibit, what is the most likely…

Exhibit

Refer to the exhibit.

# systemctl status sshd
● sshd.service - OpenSSH server daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Mon 2023-10-23 14:30:01 UTC; 5min ago
     Docs: man:sshd(8)
           man:sshd_config(5)
  Process: 1234 ExecStart=/usr/sbin/sshd -D $OPTIONS (code=exited, status=255)
 Main PID: 1234 (code=exited, status=255)

Oct 23 14:30:01 server sshd[1234]: fatal: Cannot bind to port 22: Address already in use

Based on the exhibit, what is the most likely cause of the sshd service failure?

⚠ Common exam trap

A common mix-up: candidates assume a firewall or permission issue is the cause, but the specific 'Address already in use' error directly points to a port conflict, which is a distinct and common scenario on Linux systems.

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

Another process is already listening on port 22

The sshd service failed because another process is already listening on port 22, which prevents sshd from binding to that port. This is indicated by the error message in the exhibit (e.g., 'bind: Address already in use'), which is a common symptom when a conflicting service or a previously running instance of sshd occupies the port. The system cannot start a new instance of sshd until the port is freed.

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 firewall is blocking port 22

    Why it's wrong here

    Firewall would not cause 'address in use' error.

  • The sshd configuration file has incorrect permissions

    Why it's wrong here

    Would show permission denied, not address in use.

  • The sshd service is not installed

    Why it's wrong here

    The service file exists, so it is installed.

  • Another process is already listening on port 22

    Why this is correct

    Error message directly indicates address already in use.

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JA

Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

This XK0-006 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 XK0-006 exam.