Quick Answer
The answer is the `configure` command. This is correct because Junos operates with two distinct CLI modes: operational mode for monitoring and troubleshooting, and configuration mode for making changes to the device’s active or candidate configuration. When an administrator needs to modify settings, they must first enter configuration mode by typing `configure` at the operational prompt, which transitions the CLI to the `[edit]` hierarchy. On the JNCIA-Junos exam, this concept tests your understanding of Junos mode navigation—a foundational skill that often appears in questions about basic device management. A common trap is confusing `configure` with `edit`, but remember that `configure` enters the top of the configuration hierarchy, while `edit` navigates within it. A helpful memory tip: think of `configure` as the key that unlocks the door to making changes—without it, you’re stuck in read-only operational mode.
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.
An administrator wants to navigate to the configuration mode to make changes to the device. 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.
set
Why wrong: Used to set parameters in configuration mode.
edit
Why wrong: Used within configuration mode to navigate.
configure
Enters configuration mode.
cli
Why wrong: Not a valid command to enter configuration mode.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
configure
The correct command to enter configuration mode on a Juniper device is 'configure'. This command transitions the CLI from operational mode to configuration mode, allowing the administrator to make changes to the device's configuration. In JUNOS, the CLI has two distinct modes: operational mode (for monitoring and troubleshooting) and configuration mode (for modifying the active or candidate configuration).
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.
set
Why it's wrong here
Used to set parameters in configuration mode.
edit
Why it's wrong here
Used within configuration mode to navigate.
configure
Why this is correct
Enters configuration mode.
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.
cli
Why it's wrong here
Not a valid command to enter configuration mode.
Common exam traps
The trap here is that Cisco engineers often confuse 'configure terminal' (Cisco IOS) with JUNOS commands, mistakenly thinking 'set' or 'edit' are the entry points to configuration mode, when in fact 'configure' is the required command to enter configuration mode from operational mode.
Trap categories for this question
Command / output trap
Not a valid command to enter configuration mode.
Detailed technical explanation
When you enter configuration mode using 'configure', JUNOS creates a candidate configuration that is a copy of the active configuration. All changes are made to this candidate configuration until you commit them, which applies the changes atomically. This two-phase commit model (candidate and active) allows for validation and rollback, preventing partial or incorrect changes from disrupting the device.
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.
User Interfaces — study guide chapter
Learn the concepts, then practise the questions
User Interfaces 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
User Interfaces — This question tests User Interfaces — Read the scenario before looking for a memorised answer..
The correct answer is: configure — The correct command to enter configuration mode on a Juniper device is 'configure'. This command transitions the CLI from operational mode to configuration mode, allowing the administrator to make changes to the device's configuration. In JUNOS, the CLI has two distinct modes: operational mode (for monitoring and troubleshooting) and configuration mode (for modifying the active or candidate configuration).
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 →
Same concept, more angles
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. An engineer needs to view the current active configuration of a Junos device without making any changes. Which CLI mode should they use?
easyWhy A: Operational mode is the default CLI mode in Junos, used for monitoring, troubleshooting, and viewing the current active configuration without making any changes. Commands in this mode are read-only and do not modify the device's configuration. The active configuration is the one currently running on the device, and it can be viewed using commands like 'show configuration' in operational mode.
Variation 2. Refer to the exhibit. An engineer configures a new IPv6 address on ge-0/0/0 unit 0 by entering the following commands in configuration mode: set interfaces ge-0/0/0 unit 0 family inet6 address 2001:db8::2/64 commit After the commit, the engineer runs 'show interfaces terse ge-0/0/0' and sees only the two original addresses. What is the most likely cause?
hardWhy B: Option B is correct because the engineer likely ran the 'set' command from operational mode (e.g., at the '>' prompt) rather than from configuration mode (e.g., at the '#' prompt). In Junos, 'set' commands only take effect when entered in configuration mode; if entered in operational mode, they are silently ignored or produce an error, and the configuration is not modified. Since the engineer saw no new address after commit, the 'set' command was never applied to the candidate configuration.
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.