This N10-009 practice question tests your understanding of network operations. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 technician notices a high volume of broadcast traffic on a flat network. Which device will best reduce the size of the broadcast domain?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Why wrong: Hubs operate at Layer 1 and simply repeat signals out all ports, making the entire network one collision and one broadcast domain.
B
Switch
Why wrong: Switches isolate collision domains per port but forward broadcast frames to all ports in the same VLAN, thus not reducing broadcast domain size unless VLANs are used.
C
Router
Routers operate at Layer 3 and do not forward broadcasts by default. By creating separate subnets and using a router, broadcast traffic is confined to each subnet.
D
Bridge
Why wrong: Bridges segment collision domains but forward broadcasts to all segments, so they do not reduce broadcast domains.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Router
A router is the correct choice because it operates at Layer 3 and uses IP subnetting to segment a network into separate broadcast domains. By default, routers do not forward broadcast traffic (e.g., ARP requests sent to 255.255.255.255 or subnet-directed broadcasts) between interfaces, thus reducing the scope of broadcast propagation.
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.
✗
Hub
Why it's wrong here
Hubs operate at Layer 1 and simply repeat signals out all ports, making the entire network one collision and one broadcast domain.
✗
Switch
Why it's wrong here
Switches isolate collision domains per port but forward broadcast frames to all ports in the same VLAN, thus not reducing broadcast domain size unless VLANs are used.
✓
Router
Why this is correct
Routers operate at Layer 3 and do not forward broadcasts by default. By creating separate subnets and using a router, broadcast traffic is confined to each subnet.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Bridge
Why it's wrong here
Bridges segment collision domains but forward broadcasts to all segments, so they do not reduce broadcast domains.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse broadcast domains with collision domains, incorrectly assuming that a switch reduces broadcast domains because it reduces collision domains, but a switch only segments collision domains while leaving broadcast domains intact.
Detailed technical explanation
How to think about this question
Under the hood, a router examines the destination IP address of a packet; if the destination is a broadcast address (e.g., 255.255.255.255 or the subnet broadcast), the router drops the packet rather than forwarding it to other subnets. In real-world scenarios, segmenting a flat /16 network into multiple /24 subnets with a router can cut broadcast traffic by a factor of 256, significantly reducing unnecessary processing on hosts and switches.
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 network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this N10-009 question in full detail.
Network Operations — This question tests Network Operations — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Router — A router is the correct choice because it operates at Layer 3 and uses IP subnetting to segment a network into separate broadcast domains. By default, routers do not forward broadcast traffic (e.g., ARP requests sent to 255.255.255.255 or subnet-directed broadcasts) between interfaces, thus reducing the scope of broadcast propagation.
What should I do if I get this N10-009 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
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 N10-009 practice question is part of Courseiva's free CompTIA 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 N10-009 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.