Quick Answer
The answer is to add the option "limit 100" to the monitor traffic command. This is correct because the monitor traffic command in Junos captures live packets for real-time analysis, and the limit parameter explicitly tells the command to stop after processing a specified number of packets—in this case, 100. Without this option, the capture would run indefinitely until manually interrupted, which is inefficient for controlled troubleshooting. On the JNCIA-Junos exam, this tests your understanding of operational monitoring commands and their syntax, often appearing as a straightforward configuration or troubleshooting scenario. A common trap is confusing limit with count or duration, but remember that limit is the Junos-specific parameter for packet count termination. For a quick memory tip, think "limit the load"—the limit option caps the packet count, preventing an endless stream of data from overwhelming your terminal or analysis.
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 network operator is using the 'monitor traffic' command but wants to stop after capturing 100 packets. Which option should be added?
size 100
Why wrong: 'size' limits the capture buffer size, not the packet count.
packets 100
Why wrong: 'packets' is not a valid option; the correct keyword is 'limit'.
limit 100
Correctly limits the packet capture to 100 packets.
count 100
Why wrong: 'count' is not a valid option for 'monitor traffic'.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
limit 100
The 'monitor traffic' command in Junos captures packets for analysis. To stop the capture after a specific number of packets, the correct option is 'limit 100', which instructs the command to terminate after processing 100 packets. This is a Junos-specific parameter for controlling the capture duration.
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.
size 100
Why it's wrong here
'size' limits the capture buffer size, not the packet count.
packets 100
Why it's wrong here
'packets' is not a valid option; the correct keyword is 'limit'.
limit 100
Why this is correct
Correctly limits the packet capture to 100 packets.
Related concept
Read the scenario before looking for a memorised answer.
count 100
Why it's wrong here
'count' is not a valid option for 'monitor traffic'.
Common exam traps
The trap here is that candidates may confuse Junos syntax with Cisco IOS, where 'packets' or 'count' are used in similar commands, leading them to select 'packets 100' or 'count 100' instead of the correct Junos-specific 'limit 100'.
Trap categories for this question
Keyword trap
'packets' is not a valid option; the correct keyword is 'limit'.
Detailed technical explanation
The 'monitor traffic' command leverages the Junos packet capture infrastructure, which can be configured with various options like 'limit', 'size', 'write-file', and 'matching'. The 'limit' option is essential for controlling the capture in production environments to avoid overwhelming the system or generating excessive output, especially when troubleshooting intermittent issues. Under the hood, Junos uses the Packet Forwarding Engine (PFE) to capture packets, and the 'limit' parameter ensures the capture stops gracefully without manual intervention.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
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: limit 100 — The 'monitor traffic' command in Junos captures packets for analysis. To stop the capture after a specific number of packets, the correct option is 'limit 100', which instructs the command to terminate after processing 100 packets. This is a Junos-specific parameter for controlling the capture duration.
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.
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 →
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.