Quick Answer
The answer is `rollback 0`. This command is the correct choice because Junos maintains a history of the last 50 committed configurations, with index 0 always pointing to the currently active, committed configuration. When you issue `rollback 0`, you are instructing the system to discard all uncommitted changes in the candidate configuration and replace them exactly with the active configuration, effectively starting fresh from the last committed state. On the JNCIA-Junos exam, this question tests your understanding of configuration management and the rollback feature, often appearing as a direct command-choice item. A common trap is confusing `rollback 0` with `rollback 1`, which reverts to the previous committed configuration rather than the current active one. Remember the memory tip: "Zero is the hero" — index 0 always represents the active, committed configuration, so rolling back to zero wipes out any uncommitted edits and gives you a clean slate.
This JNCIA-JUNOS practice question tests your understanding of junos configuration basics. 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.
An engineer wants to revert all uncommitted changes in the candidate configuration and start fresh from the currently active configuration. Which command should be used?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "which command"
Why it matters: Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
rollback 0
This sets the candidate to match the active configuration, discarding uncommitted changes.
commit check
Why wrong: This checks syntax but does not revert uncommitted changes.
rollback 1
Why wrong: This reverts to the previous commit, not the current active.
load override terminal
Why wrong: This replaces the candidate configuration with manually entered configuration, not with the active configuration.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
rollback 0
The `rollback 0` command reverts all uncommitted changes in the candidate configuration and restores it to match the currently active configuration (the one most recently committed). This is because Junos stores the last 50 committed configurations, with index 0 always representing the active configuration. Using `rollback 0` effectively discards any uncommitted edits and starts fresh from the last committed state.
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.
rollback 0
Why this is correct
This sets the candidate to match the active configuration, discarding uncommitted changes.
Clue confirmation
The clue word "which command" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
commit check
Why it's wrong here
This checks syntax but does not revert uncommitted changes.
rollback 1
Why it's wrong here
This reverts to the previous commit, not the current active.
load override terminal
Why it's wrong here
This replaces the candidate configuration with manually entered configuration, not with the active configuration.
Common exam traps
The trap here is that candidates often confuse `rollback 0` with `rollback 1`, mistakenly thinking that `rollback 1` reverts uncommitted changes, when in fact `rollback 1` reverts to the configuration before the last commit, not the current active configuration.
Detailed technical explanation
Junos maintains a rollback history of the last 50 committed configurations, stored as numbered files (e.g., juniper.conf.0 through juniper.conf.49) in the /config directory. Index 0 always points to the currently active configuration, while higher indices represent older commits. The `rollback 0` command copies the active configuration into the candidate configuration, effectively discarding any uncommitted edits. This is distinct from `rollback 1`, which restores the configuration from the previous commit, useful for undoing a recent commit but not for clearing uncommitted changes.
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 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
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Junos Configuration Basics — study guide chapter
Learn the concepts, then practise the questions
Junos Configuration Basics practice questions
Targeted practice on this topic area only
All JNCIA-JUNOS questions
514 questions across all exam domains
Juniper Networks Certified Associate Junos JNCIA-Junos study guide
Full concept coverage aligned to exam objectives
JNCIA-JUNOS practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise JNCIA-JUNOS questions linked to User Interfaces.
Practise JNCIA-JUNOS questions linked to Junos Configuration Basics.
Practise JNCIA-JUNOS questions linked to Operational Monitoring and Maintenance.
Practise JNCIA-JUNOS questions linked to Routing Fundamentals.
Practise JNCIA-JUNOS questions linked to Networking Fundamentals.
Practise JNCIA-JUNOS questions linked to Junos OS Fundamentals.
Practise JNCIA-JUNOS questions linked to JNCIA-JUNOS fundamentals.
Practise JNCIA-JUNOS questions linked to JNCIA-JUNOS scenario.
Practise JNCIA-JUNOS questions linked to JNCIA-JUNOS troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Junos Configuration Basics — This question tests Junos Configuration Basics — Read the scenario before looking for a memorised answer..
The correct answer is: rollback 0 — The `rollback 0` command reverts all uncommitted changes in the candidate configuration and restores it to match the currently active configuration (the one most recently committed). This is because Junos stores the last 50 committed configurations, with index 0 always representing the active configuration. Using `rollback 0` effectively discards any uncommitted edits and starts fresh from the last committed state.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Yes — watch for: "which command". Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
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 →
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.
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.