This LPIC-1 practice question tests your understanding of essential system services and networking. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
Refer to the exhibit. The administrator is unable to SSH into the server (TCP port 22) from a remote host. The iptables rules are as shown. What is the most likely cause?
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.
The default policy is ACCEPT, so SSH should be accepted.
Why wrong: Explicit DROP overrides default policy.
The second rule drops all incoming traffic, including SSH.
The DROP rule matches all traffic not yet matched.
The SSH service is not running.
Why wrong: The issue is firewall, not service.
The first rule only allows loopback, not SSH.
Why wrong: Loopback rule allows lo interface only, not external SSH.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
The second rule drops all incoming traffic, including SSH.
Option A is correct: the last rule drops all incoming traffic, and there is no rule allowing SSH. Option B is wrong because the default policy is ACCEPT, but the DROP rule supersedes. Option C is wrong because the loopback rule allows lo only. Option D is wrong because the policy is ACCEPT but the explicit DROP rule catches all.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
The default policy is ACCEPT, so SSH should be accepted.
Why it's wrong here
Explicit DROP overrides default policy.
The second rule drops all incoming traffic, including SSH.
Why this is correct
The DROP rule matches all traffic not yet matched.
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.
The SSH service is not running.
Why it's wrong here
The issue is firewall, not service.
The first rule only allows loopback, not SSH.
Why it's wrong here
Loopback rule allows lo interface only, not external SSH.
Common exam traps
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the LPIC-1 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
Identify which LPIC-1 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Essential System Services and Networking — study guide chapter
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FAQ
Essential System Services and Networking — This question tests Essential System Services and Networking — Read the scenario before looking for a memorised answer..
The correct answer is: The second rule drops all incoming traffic, including SSH. — Option A is correct: the last rule drops all incoming traffic, and there is no rule allowing SSH. Option B is wrong because the default policy is ACCEPT, but the DROP rule supersedes. Option C is wrong because the loopback rule allows lo only. Option D is wrong because the policy is ACCEPT but the explicit DROP rule catches all.
Identify which LPIC-1 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 24, 2026
This LPIC-1 practice question is part of Courseiva's free LPI 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 LPIC-1 exam.
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