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 about the Junos commit model are true?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
A commit makes the candidate configuration the active configuration.
Option A is correct because the Junos commit model uses a two-phase process: changes are made to the candidate configuration, and the `commit` command activates that candidate configuration as the new active configuration. This ensures that changes are not applied until explicitly committed, providing a safe and predictable way to modify the device's operational state.
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.
✓
A commit makes the candidate configuration the active configuration.
Why this is correct
A is true.
Related concept
Read the scenario before looking for a memorised answer.
✗
The commit command is used to discard changes.
Why it's wrong here
E is false; commit activates changes.
✓
The rollback command can be used to revert to a previous configuration.
Why this is correct
D is true.
Related concept
Read the scenario before looking for a memorised answer.
✗
A commit validation is performed automatically before commit.
Why it's wrong here
B is false; commit check is manual.
✗
Multiple candidates can be active simultaneously.
Why it's wrong here
C is false; only one candidate.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is confusing the `commit` command with discarding changes (Option B) or assuming automatic validation (Option D), which are common misconceptions from other vendor CLI behaviors like Cisco IOS where `write memory` saves immediately and validation is often implicit.
Detailed technical explanation
How to think about this question
Under the hood, Junos maintains two configuration databases: the candidate configuration (a working copy) and the active configuration (the running config). The `commit` command performs a syntax check, applies the changes, and updates the active configuration, while also saving a rollback snapshot (up to 50 previous configurations by default). In real-world scenarios, this model allows network engineers to stage complex changes and validate them with `commit check` before applying, reducing the risk of misconfiguration that could cause outages.
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.
TExam Day Tips
→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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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: A commit makes the candidate configuration the active configuration. — Option A is correct because the Junos commit model uses a two-phase process: changes are made to the candidate configuration, and the `commit` command activates that candidate configuration as the new active configuration. This ensures that changes are not applied until explicitly committed, providing a safe and predictable way to modify the device's operational state.
What should I do if I get this JNCIA-JUNOS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.