Quick Answer
The answer is the commit check command. This command validates the candidate configuration for syntax errors without committing it, making it the ideal tool when a junior admin receives a 'commit error: syntax error' message due to a missing closing brace. Unlike a full commit, which would reject the entire configuration, commit check scans the candidate configuration and outputs the exact line number and file where the error occurs, allowing precise troubleshooting. On the JNCIA-Junos exam, this tests your understanding of Junos operational commands for safe configuration management, often appearing in scenarios where you must differentiate commit check from commit confirmed or rollback. A common trap is confusing commit check with commit synchronize, but remember: check is for validation, not activation. Memory tip: think of commit check as a "dry run" that catches syntax errors before you commit, saving you from a locked configuration.
This JNCIA-JUNOS practice question tests your understanding of user interfaces. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 junior admin tries to commit a configuration but receives a 'commit error: syntax error' message. They suspect a missing closing brace. Which CLI command helps identify the exact line with the error?
commit check
Validates the candidate configuration and reports syntax errors with exact line numbers.
rollback 0
Why wrong: Reverts to the active configuration, not helpful for finding the error.
load merge
Why wrong: Loads a configuration file, does not check syntax.
show configuration
Why wrong: Displays configuration but does not validate syntax.
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 check
The 'commit check' command validates the candidate configuration for syntax errors without committing it. When a syntax error like a missing closing brace is present, commit check outputs the exact line number and file where the error occurs, allowing the admin to locate and fix the issue before attempting a commit again.
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.
commit check
Why this is correct
Validates the candidate configuration and reports syntax errors with exact line numbers.
Related concept
Read the scenario before looking for a memorised answer.
rollback 0
Why it's wrong here
Reverts to the active configuration, not helpful for finding the error.
load merge
Why it's wrong here
Loads a configuration file, does not check syntax.
show configuration
Why it's wrong here
Displays configuration but does not validate syntax.
Common exam traps
The trap here is that candidates may confuse 'show configuration' with a validation tool, not realizing it only displays the configuration text without any syntax checking, whereas 'commit check' is the dedicated command for identifying syntax errors before commit.
Detailed technical explanation
Under the hood, Junos uses a commit model where the candidate configuration is stored in a separate database. The 'commit check' command invokes the same syntax and semantic validation routines as a full commit, including checks for missing braces, invalid statements, and unresolvable references, but stops before applying the configuration. This is particularly useful in automated scripts or when making complex changes, as it prevents commit failures that could disrupt network operations.
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.
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FAQ
User Interfaces — This question tests User Interfaces — Read the scenario before looking for a memorised answer..
The correct answer is: commit check — The 'commit check' command validates the candidate configuration for syntax errors without committing it. When a syntax error like a missing closing brace is present, commit check outputs the exact line number and file where the error occurs, allowing the admin to locate and fix the issue before attempting a commit again.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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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.
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