- A
The commit operation validates the configuration before applying.
Junos performs validation checks (syntax, semantics) before applying the commit. If validation fails, the commit is rejected.
- B
The commit operation can be confirmed with a time delay.
The 'commit confirm' command applies a configuration temporarily, and if not confirmed within a timeout (default 10 minutes), it automatically rolls back to the previous configuration.
- C
The candidate configuration is activated immediately upon commit.
Why wrong: False. While a regular commit activates immediately, commands like 'commit confirmed' or 'commit at' introduce delays, so activation is not always immediate upon commit.
- D
The commit operation always requires a reboot.
Why wrong: Most configuration changes do not require a reboot. Only changes affecting the kernel (e.g., certain package installations) may require a reboot.
- E
A commit check can be performed without committing.
True. The 'commit check' command validates the configuration without committing it, making this statement true about the commit operation context.
Understanding the Commit Operation in Junos
This JNCIA-JUNOS practice question tests your understanding of operational monitoring and maintenance. 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 THREE statements are true about the commit operation on Junos?
Quick Answer
The answer is that the commit operation in Junos activates the candidate configuration immediately upon commit, but only after it passes validation. This is correct because Junos uses a two-phase model: changes are first made to a candidate configuration, and then the commit command validates both syntax and semantics before applying the configuration to the running system. If validation fails, the commit is aborted and the candidate configuration remains unchanged, preventing operational disruptions. On the JNCIA-Junos exam, this concept tests your understanding of Junos operational stability and the commit process, often appearing in questions that ask which statements are true about the commit operation. A common trap is assuming a commit always applies changes instantly without validation, but Junos always validates first. Remember the mnemonic "Validate Before Activate" to recall that a commit checks for errors before making changes live.
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
The commit operation validates the configuration before applying.
Options A, B, and E are true statements about the commit operation. Option A is correct because the commit operation validates the configuration before applying. Option B is correct because the commit confirmed command allows a commit with a time delay for rollback. Option E is correct because a commit check can be performed without actually committing the configuration, which is a related but separate action. Option C is false because the candidate configuration is not always activated immediately upon commit; for example, 'commit at' or 'commit confirmed' can defer or delay activation. Option D is false because a commit does not require a reboot.
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.
- ✓
The commit operation validates the configuration before applying.
Why this is correct
Junos performs validation checks (syntax, semantics) before applying the commit. If validation fails, the commit is rejected.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
The commit operation can be confirmed with a time delay.
Why this is correct
The 'commit confirm' command applies a configuration temporarily, and if not confirmed within a timeout (default 10 minutes), it automatically rolls back to the previous configuration.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The candidate configuration is activated immediately upon commit.
Why it's wrong here
False. While a regular commit activates immediately, commands like 'commit confirmed' or 'commit at' introduce delays, so activation is not always immediate upon commit.
- ✗
The commit operation always requires a reboot.
Why it's wrong here
Most configuration changes do not require a reboot. Only changes affecting the kernel (e.g., certain package installations) may require a reboot.
- ✓
A commit check can be performed without committing.
Why this is correct
True. The 'commit check' command validates the configuration without committing it, making this statement true about the commit operation context.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap is that candidates may include option C, thinking activation is always immediate, or exclude option E because they consider commit check separate. However, commit check is a valid related ability.
Trap categories for this question
Command / output trap
False. While a regular commit activates immediately, commands like 'commit confirmed' or 'commit at' introduce delays, so activation is not always immediate upon commit.
Detailed technical explanation
How to think about this question
Under the hood, the commit operation triggers a series of checks including schema validation, referential integrity, and application-specific constraints. The candidate configuration is stored in a separate database and only becomes the active configuration after a successful commit, which updates the `/config/juniper.conf.gz` file and applies changes to the running processes without a reboot.
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.
- →
Operational Monitoring and Maintenance — study guide chapter
Learn the concepts, then practise the questions
- →
Operational Monitoring and Maintenance 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
Related JNCIA-JUNOS practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
User Interfaces practice questions
Practise JNCIA-JUNOS questions linked to User Interfaces.
Junos Configuration Basics practice questions
Practise JNCIA-JUNOS questions linked to Junos Configuration Basics.
Operational Monitoring and Maintenance practice questions
Practise JNCIA-JUNOS questions linked to Operational Monitoring and Maintenance.
Routing Fundamentals practice questions
Practise JNCIA-JUNOS questions linked to Routing Fundamentals.
Networking Fundamentals practice questions
Practise JNCIA-JUNOS questions linked to Networking Fundamentals.
Junos OS Fundamentals practice questions
Practise JNCIA-JUNOS questions linked to Junos OS Fundamentals.
JNCIA-JUNOS fundamentals practice questions
Practise JNCIA-JUNOS questions linked to JNCIA-JUNOS fundamentals.
JNCIA-JUNOS scenario practice questions
Practise JNCIA-JUNOS questions linked to JNCIA-JUNOS scenario.
JNCIA-JUNOS troubleshooting practice questions
Practise JNCIA-JUNOS questions linked to JNCIA-JUNOS troubleshooting.
Practice this exam
Start a free JNCIA-JUNOS practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this JNCIA-JUNOS question test?
Operational Monitoring and Maintenance — This question tests Operational Monitoring and Maintenance — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The commit operation validates the configuration before applying. — Options A, B, and E are true statements about the commit operation. Option A is correct because the commit operation validates the configuration before applying. Option B is correct because the commit confirmed command allows a commit with a time delay for rollback. Option E is correct because a commit check can be performed without actually committing the configuration, which is a related but separate action. Option C is false because the candidate configuration is not always activated immediately upon commit; for example, 'commit at' or 'commit confirmed' can defer or delay activation. Option D is false because a commit does not require a reboot.
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 →
Keep practising
More JNCIA-JUNOS practice questions
- A junior engineer needs to collect a snapshot of the current system state, including routing tables, interfaces, and con…
- A network engineer is troubleshooting a connectivity issue and wants to see the active routes in the routing table. Whic…
- You are the network engineer for a mid-sized enterprise with a Juniper MX router running Junos. The router has two uplin…
- Which TWO attributes are used by Junos to select the active route among multiple routes to the same destination?
- What is the default preference of a direct route in Junos?
- A router has two routes to the same destination: one with preference 10 and metric 5, and another with preference 15 and…
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.