The correct answer is that the '| except' pipe filter displays lines that do not match a regular expression, while the '| match' filter shows only lines containing a match, and the '| count' filter tallies the total number of output lines. These three filters are fundamental to the Junos CLI pipe system, which allows you to refine command output by applying a regular expression directly after the pipe symbol. On the JNCIA-Junos exam, this topic tests your ability to quickly isolate operational or configuration data without scrolling through entire output, a skill critical for real-world troubleshooting. A common trap is confusing '| except' with '| match'—remember that 'except' excludes the pattern, while 'match' includes it. For a quick memory tip, think of the pipe as a funnel: 'match' keeps what fits, 'except' throws it away, and 'count' just measures the flow.
JNCIA-JUNOS User Interfaces Practice Question
This JNCIA-JUNOS practice question tests your understanding of user interfaces. 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 about JunOS CLI pipe commands are true? (Choose three.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The '| match' pipe filter displays lines that match a regular expression.
Option A is correct because the '| match' pipe filter in JunOS uses a regular expression to display only those lines in the output that contain a match. This is a standard filtering mechanism that allows operators to quickly isolate relevant configuration or operational data without scrolling through entire command output.
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 '| match' pipe filter displays lines that match a regular expression.
Why this is correct
This is a fundamental use of the pipe filter.
Related concept
Read the scenario before looking for a memorised answer.
✓
The '| count' pipe filter counts the number of lines in the output.
Why this is correct
This is used to get a line count.
Related concept
Read the scenario before looking for a memorised answer.
✓
The '| except' pipe filter displays lines that do not match a regular expression.
Why this is correct
This is the inverse of '| match'.
Related concept
Read the scenario before looking for a memorised answer.
✗
The '| resolve' pipe filter resolves IP addresses to hostnames.
Why it's wrong here
This pipe is used in configuration mode to resolve addresses in the displayed configuration, not in operational output.
✗
The '| display set' pipe filter converts operational output to set format.
Why it's wrong here
It only works on configuration output to display it in set format; it does not convert operational output.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse '| resolve' with DNS resolution of addresses in the output, but it only performs reverse lookups and does not modify the output format or filter lines.
Trap categories for this question
Command / output trap
This pipe is used in configuration mode to resolve addresses in the displayed configuration, not in operational output.
Detailed technical explanation
How to think about this question
JunOS pipe filters are processed sequentially by the CLI parser, which applies each filter to the output buffer before passing it to the next filter or to the terminal. The '| match' filter uses the same regular expression engine as the 'show' command's 'match' option, supporting POSIX extended regular expressions. In real-world troubleshooting, '| match' is often combined with '| count' to quickly assess how many interfaces, routes, or BGP peers match a specific pattern, such as '| match ge-0/0/0 | count' to see how many interfaces in a particular FPC slot are present.
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.
User Interfaces — This question tests User Interfaces — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The '| match' pipe filter displays lines that match a regular expression. — Option A is correct because the '| match' pipe filter in JunOS uses a regular expression to display only those lines in the output that contain a match. This is a standard filtering mechanism that allows operators to quickly isolate relevant configuration or operational data without scrolling through entire command output.
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 →
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.
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.