Quick Answer
The answer is to type **show ?** (show space question mark). This keystroke invokes Junos context-sensitive help, which displays all commands available in operational mode that start with the partial string “show.” The question mark acts as a wildcard for the next word, listing every possible completion—such as `show interfaces`, `show configuration`, and `show route`—without executing any command. On the JNCIA-Junos exam, this tests your understanding of Junos CLI help fundamentals, where the question mark is the primary tool for command discovery and tab completion is used to auto-complete a known command. A common trap is confusing the question mark with the Tab key: Tab completes a single command if unique, while the question mark shows all possibilities. Remember the mnemonic “**? for list, Tab for finish**” to keep them straight during the exam.
This JNCIA-JUNOS practice question tests your understanding of user interfaces. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 wants to see all commands available in operational mode that start with 'show'. What keystrokes should they use?
show ? + Enter
Why wrong: The question mark alone does not execute; pressing Enter after ? may cause unexpected behavior.
show ?
Correctly lists all subcommands available under 'show'.
show + ?
Why wrong: Incorrect syntax; the space before ? is required.
show <Tab>
Why wrong: Auto-completes the current keyword if unique, but does not list all options.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
show ?
Option B is correct because in Junos operational mode, typing 'show ?' and pressing Enter (or just 'show ?' without Enter) displays all commands that start with 'show'. The question mark (?) is the context-sensitive help key that lists available completions for the current partial command. Pressing Enter after 'show ?' is optional but acceptable; the key behavior is the space followed by ?.
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.
show ? + Enter
Why it's wrong here
The question mark alone does not execute; pressing Enter after ? may cause unexpected behavior.
show ?
Why this is correct
Correctly lists all subcommands available under 'show'.
Related concept
Read the scenario before looking for a memorised answer.
show + ?
Why it's wrong here
Incorrect syntax; the space before ? is required.
show <Tab>
Why it's wrong here
Auto-completes the current keyword if unique, but does not list all options.
Common exam traps
The trap here is that candidates familiar with Cisco IOS might confuse the Junos ? help with Cisco's ? or Tab behavior, where Tab in Cisco completes the command and ? lists options, but in Junos, Tab also completes but ? with a space lists all commands starting with the partial string, not just next keywords.
Trap categories for this question
Keyword trap
Auto-completes the current keyword if unique, but does not list all options.
Detailed technical explanation
Junos uses a context-sensitive help system where typing a partial command followed by a space and then ? displays all possible next keywords or arguments. For example, 'show ?' lists all show subcommands like interfaces, route, configuration, etc. This is distinct from the '?' without a space, which repeats the current command or lists options for the immediately preceding token. In real-world scenarios, this helps administrators quickly discover available operational mode commands without memorizing the entire CLI tree.
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: show ? — Option B is correct because in Junos operational mode, typing 'show ?' and pressing Enter (or just 'show ?' without Enter) displays all commands that start with 'show'. The question mark (?) is the context-sensitive help key that lists available completions for the current partial command. Pressing Enter after 'show ?' is optional but acceptable; the key behavior is the space followed by ?.
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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