- A
The 'commit check' command applies the candidate configuration to the active configuration.
Why wrong: 'commit check' only validates the syntax; it does not apply the configuration.
- B
The 'load replace' command merges a configuration file into the candidate configuration.
Why wrong: 'load replace' replaces the entire candidate configuration; 'load merge' merges.
- C
The 'show | compare' command displays differences between the candidate and active configurations.
'show | compare' shows how the candidate configuration differs from the active.
- D
The 'rollback 0' command reverts the candidate configuration to the previous state.
Why wrong: 'rollback 0' reverts the candidate to the most recently committed configuration, not the previous state.
- E
The 'set' command is used to modify the candidate configuration.
The 'set' command adds or changes configuration statements in the candidate configuration.
Quick Answer
The correct answer identifies that the 'set' command modifies the candidate configuration and that 'show | compare' displays differences between the candidate and active configurations. These two statements are correct because the Junos OS configuration hierarchy operates on a two-phase model: you first modify a private candidate configuration using commands like 'set', and then you must commit those changes to make them active. The 'show | compare' command is essential for reviewing exactly what you have changed before committing, showing a diff-style output. On the JNCIA-Junos exam, this concept tests your understanding of the commit model and the candidate configuration workflow, often appearing in questions that try to confuse 'commit check' (which only validates syntax) with actually applying changes. A common trap is assuming 'rollback 0' reverts to the candidate configuration, but it actually reverts to the most recently committed configuration. Memory tip: think of 'set' as your pencil for editing a draft, and 'show | compare' as your proofreader showing the redline changes before you finalize the document.
JNCIA-JUNOS Junos OS Fundamentals Practice Question
This JNCIA-JUNOS practice question tests your understanding of junos os fundamentals. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
Which TWO statements are correct regarding the Junos OS configuration hierarchy?
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 'show | compare' command displays differences between the candidate and active configurations.
Option A is correct because the 'set' command modifies candidate configuration. Option D is correct because the 'show | compare' command displays differences between candidate and active. Option B is wrong because 'commit check' only validates syntax, it does not apply changes. Option C is wrong because 'rollback 0' reverts to the most recently committed configuration, not the candidate. Option E is wrong because 'load replace' replaces the entire candidate configuration, not merges.
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 'commit check' command applies the candidate configuration to the active configuration.
Why it's wrong here
'commit check' only validates the syntax; it does not apply the configuration.
- ✗
The 'load replace' command merges a configuration file into the candidate configuration.
Why it's wrong here
'load replace' replaces the entire candidate configuration; 'load merge' merges.
- ✓
The 'show | compare' command displays differences between the candidate and active configurations.
Why this is correct
'show | compare' shows how the candidate configuration differs from the active.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The 'rollback 0' command reverts the candidate configuration to the previous state.
Why it's wrong here
'rollback 0' reverts the candidate to the most recently committed configuration, not the previous state.
- ✓
The 'set' command is used to modify the candidate configuration.
Why this is correct
The 'set' command adds or changes configuration statements in the candidate configuration.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
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
How to think about this question
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.
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.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- 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 JNCIA-JUNOS 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 JNCIA-JUNOS 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.
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Junos OS Fundamentals — study guide chapter
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FAQ
Questions learners often ask
What does this JNCIA-JUNOS question test?
Junos OS Fundamentals — This question tests Junos OS Fundamentals — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The 'show | compare' command displays differences between the candidate and active configurations. — Option A is correct because the 'set' command modifies candidate configuration. Option D is correct because the 'show | compare' command displays differences between candidate and active. Option B is wrong because 'commit check' only validates syntax, it does not apply changes. Option C is wrong because 'rollback 0' reverts to the most recently committed configuration, not the candidate. Option E is wrong because 'load replace' replaces the entire candidate configuration, not merges.
What should I do if I get this JNCIA-JUNOS question wrong?
Identify which JNCIA-JUNOS 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.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 24, 2026
This JNCIA-JUNOS practice question is part of Courseiva's free Juniper Networks 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 JNCIA-JUNOS exam.
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