- A
Issue the 'rollback 0' command, then commit.
Why wrong: Rollback 0 reverts to the last committed configuration, which would undo the change.
- B
Issue the 'commit confirmed 5' command again to reset the timer.
Why wrong: Reissuing commit confirmed only restarts the timer; the configuration is still pending confirmation.
- C
Issue the 'request system reboot' command to reload the router.
Why wrong: Rebooting does not confirm the commit; it may cause unnecessary downtime.
- D
Issue a standard 'commit' command to confirm the configuration.
A standard commit makes the candidate configuration permanent and cancels the commit confirmed timer.
Quick Answer
The answer is to issue a standard commit command. When you perform a commit confirmed in Junos, the configuration is temporarily applied with a timer; making it permanent requires a second, standard commit before the timer expires, which finalizes the changes and cancels the automatic rollback. This tests your understanding of the Junos commit model, a core topic on the JNCIA-Junos exam, where the common trap is confusing validation commands like commit check with actual confirmation. Remember the simple rule: a confirmed commit is a trial run, and only a plain commit makes it stick. A useful memory tip is “confirm then commit again” — the first commit is the test, the second commit is the truth.
JNCIA-JUNOS Junos OS Fundamentals Practice Question
This JNCIA-JUNOS practice question tests your understanding of junos os fundamentals. 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.
A network engineer is configuring a new Juniper MX router to replace an existing core router. The engineer has applied several configuration changes and wants to ensure that the new configuration can be tested safely. If the test fails (e.g., loss of management connectivity), the router should automatically revert to the previous configuration after a 5-minute period. The engineer performs a commit confirmed with a timeout of 5 minutes. After 4 minutes, the engineer verifies that the change is successful and wants to make it permanent. Which action should the engineer take to ensure the configuration persists?
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
Issue a standard 'commit' command to confirm the configuration.
Option C is correct because issuing 'commit check' does not make the configuration permanent; it only validates syntax. The engineer must explicitly commit the candidate configuration to confirm it. Option A is wrong because 'rollback 0' reverts to the previous configuration, undoing the change. Option B is wrong because 'request system reboot' would interrupt operations and is unnecessary. Option D is wrong because 'commit confirmed' with a new timeout would restart the timer but does not finalize; a standard commit is needed.
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.
- ✗
Issue the 'rollback 0' command, then commit.
Why it's wrong here
Rollback 0 reverts to the last committed configuration, which would undo the change.
- ✗
Issue the 'commit confirmed 5' command again to reset the timer.
Why it's wrong here
Reissuing commit confirmed only restarts the timer; the configuration is still pending confirmation.
- ✗
Issue the 'request system reboot' command to reload the router.
Why it's wrong here
Rebooting does not confirm the commit; it may cause unnecessary downtime.
- ✓
Issue a standard 'commit' command to confirm the configuration.
Why this is correct
A standard commit makes the candidate configuration permanent and cancels the commit confirmed timer.
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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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: Issue a standard 'commit' command to confirm the configuration. — Option C is correct because issuing 'commit check' does not make the configuration permanent; it only validates syntax. The engineer must explicitly commit the candidate configuration to confirm it. Option A is wrong because 'rollback 0' reverts to the previous configuration, undoing the change. Option B is wrong because 'request system reboot' would interrupt operations and is unnecessary. Option D is wrong because 'commit confirmed' with a new timeout would restart the timer but does not finalize; a standard commit is needed.
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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