JN0-106 Junos Configuration Basics Practice Question
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?
⚠ Common exam trap
Many candidates 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.
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
✓
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.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
rollback 0
Why this is correct
In Junos, `rollback 0` directly loads the most recently committed configuration into the candidate configuration, discarding any uncommitted edits or staged changes. This makes the candidate an exact mirror of the active, running configuration without modifying that active configuration until a subsequent commit. It is the standard, intended way to revert all uncommitted changes while preserving the currently effective operational state.
- ✗
commit check
Why it's wrong here
The `commit check` command performs a syntax and validation pass over the candidate configuration, but it never alters or clears that candidate. If validation succeeds, you see a confirmation; if not, errors are reported, yet all uncommitted changes remain intact for editing. Therefore, it can only tell you whether the current changes are valid to commit, not revert or discard any of them.
- ✗
rollback 1
Why it's wrong here
`rollback 1` reaches back to the configuration from the previous commit in the rollback database, meaning the state that was active before the current active configuration. Because it selects an older committed snapshot rather than the current one, it can reintroduce outdated or removed settings instead of simply dropping uncommitted edits. To abandon changes while keeping the current active configuration, you must use `rollback 0`, not a numerically higher rollback value.
- ✗
load override terminal
Why it's wrong here
The `load override terminal` operation tells Junos to read configuration statements from the terminal, replacing the entire contents of the candidate configuration with whatever you type. That is useful for importing a complete configuration, but it has no knowledge of the active configuration or the rollback database—it simply overwrites the candidate with arbitrary input. Unless you manually retype the active settings, the candidate will not match the active configuration, so it cannot be used to revert uncommitted changes.
Go deeper
Related to this question
About these practice questions
One of 156 original JN0-106 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This JN0-106 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 JN0-106 exam.