Quick Answer
The answer is the `commit` command, which is the correct choice because it activates the candidate configuration and saves it to the active configuration database, ensuring the changes persist across reboots. In Junos, all configuration changes are made in a candidate configuration that is not active until committed; without a `commit`, any edits are lost when the device restarts or if the candidate is discarded. On the JNCIA-Junos exam, this concept tests your understanding of the Junos commit model and the difference between transient candidate changes and persistent active configurations. A common trap is confusing `commit` with `commit check` or `show | compare`—the former only validates syntax without saving, while the latter merely displays differences. Remember the memory tip: "No commit, no persistence—if you don't commit, it won't stick."
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.
A network engineer is configuring a new Juniper device and needs to ensure that the configuration is saved persistently across reboots. 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.
save
Why wrong: Not a valid Junos command for committing configuration; save is used for file operations.
request system reboot
Why wrong: Reboots the device but does not save the candidate configuration.
show configuration
Why wrong: Displays the current configuration; does not save changes.
commit
Commits the candidate configuration to the active configuration, ensuring persistence across reboots.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
commit
The `commit` command activates the candidate configuration and saves it to the active configuration database, ensuring it persists across reboots. Without a commit, any changes made in candidate mode are lost when the device restarts.
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.
save
Why it's wrong here
Not a valid Junos command for committing configuration; save is used for file operations.
request system reboot
Why it's wrong here
Reboots the device but does not save the candidate configuration.
show configuration
Why it's wrong here
Displays the current configuration; does not save changes.
commit
Why this is correct
Commits the candidate configuration to the active configuration, ensuring persistence across reboots.
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.
Common exam traps
The trap here is that candidates familiar with Cisco IOS may mistakenly think `save` or `write memory` is the equivalent command, but Junos requires an explicit `commit` to persist changes.
Trap categories for this question
Command / output trap
Not a valid Junos command for committing configuration; save is used for file operations.
Detailed technical explanation
Junos uses a two-phase commit model: changes are made in the candidate configuration and then committed with `commit`, which validates the configuration, applies it to the active database, and triggers the `commit` script. The active configuration is stored in `/config/juniper.conf.gz` and is loaded automatically on reboot. Without a commit, the candidate configuration is stored in `/var/db/config/juniper.conf.gz` but is not applied or saved persistently.
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 OS Fundamentals — study guide chapter
Learn the concepts, then practise the questions
Junos OS Fundamentals 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 OS Fundamentals — This question tests Junos OS Fundamentals — Read the scenario before looking for a memorised answer..
The correct answer is: commit — The `commit` command activates the candidate configuration and saves it to the active configuration database, ensuring it persists across reboots. Without a commit, any changes made in candidate mode are lost when the device restarts.
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 →
Keep practising
Last reviewed: Jun 11, 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.