- A
Smurf attack
The Smurf attack uses IP broadcast and spoofing to cause multiple replies to be sent to the victim, creating a flood of ICMP traffic.
- B
Ping flood
Why wrong: A ping flood typically involves the attacker sending a high volume of echo requests directly to the target, not receiving replies from many sources.
- C
ICMP tunneling
Why wrong: ICMP tunneling is a method to encapsulate data within ICMP packets for covert communication, not a flood attack.
- D
Fraggle attack
Why wrong: A Fraggle attack is similar to Smurf but uses UDP echo packets instead of ICMP.
Question 463 of 520
N10-009 Network Security Practice Question
This N10-009 practice question tests your understanding of network security. 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 security analyst notices that a web server is receiving a large number of ICMP echo reply packets from many different external hosts. The server did not send any echo requests. Which type of attack is most likely occurring?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Smurf attack
A Smurf attack exploits IP broadcast addressing and ICMP. The attacker sends a large number of ICMP echo request packets with a spoofed source IP (the victim's IP) to a network's broadcast address. All hosts on that network then send ICMP echo reply packets to the victim, overwhelming it with traffic. Since the server never sent any echo requests, the unsolicited flood of echo replies is the hallmark of a Smurf attack.
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.
- ✓
Smurf attack
Why this is correct
The Smurf attack uses IP broadcast and spoofing to cause multiple replies to be sent to the victim, creating a flood of ICMP traffic.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Ping flood
Why it's wrong here
A ping flood typically involves the attacker sending a high volume of echo requests directly to the target, not receiving replies from many sources.
When this WOULD be correct
A ping flood would be correct if the question described a server receiving a high volume of ICMP echo request packets from a single or multiple sources, causing resource exhaustion, without any mention of unsolicited replies.
- ✗
ICMP tunneling
Why it's wrong here
ICMP tunneling is a method to encapsulate data within ICMP packets for covert communication, not a flood attack.
- ✗
Fraggle attack
When this WOULD be correct
A Fraggle attack would be correct if the question described a large number of UDP echo or chargen packets from many external hosts targeting a victim, with the victim not sending any such requests.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The N10-009 exam frequently reuses these exact scenarios with slightly different constraints.
✓Smurf attackCorrect answer▾
Why this is correct
The Smurf attack uses IP broadcast and spoofing to cause multiple replies to be sent to the victim, creating a flood of ICMP traffic.
✗Ping floodWrong answer — click to see why▾
Why this is wrong here
A ping flood directly targets a victim by overwhelming it with ICMP echo request packets, not echo replies. The question states the server receives echo replies without sending requests, which is characteristic of a Smurf attack that amplifies replies from many hosts.
★ When this WOULD be the correct answer
A ping flood would be correct if the question described a server receiving a high volume of ICMP echo request packets from a single or multiple sources, causing resource exhaustion, without any mention of unsolicited replies.
Why candidates choose this
Candidates may confuse 'ping flood' with any ICMP-based denial-of-service attack, overlooking the specific distinction between echo requests (ping flood) and echo replies (Smurf attack).
✗Fraggle attackWrong answer — click to see why▾
Why this is wrong here
A Fraggle attack uses UDP echo (port 7) or chargen (port 19) traffic, not ICMP echo reply packets. The question specifies ICMP echo replies, which are characteristic of a Smurf attack.
★ When this WOULD be the correct answer
A Fraggle attack would be correct if the question described a large number of UDP echo or chargen packets from many external hosts targeting a victim, with the victim not sending any such requests.
Why candidates choose this
Candidates may confuse Fraggle with Smurf because both are amplification attacks that use spoofed source addresses and broadcast traffic; the key difference is the protocol (UDP vs ICMP).
Analysis generated from the official N10-009blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
The N10-009 exam often tests the distinction between a Smurf attack (unsolicited replies from many hosts due to a spoofed broadcast request) and a ping flood (direct requests from the attacker to the victim), so candidates mistakenly choose 'ping flood' when they see a flood of ICMP traffic.
Trap categories for this question
Similar concept trap
A Fraggle attack is similar to Smurf but uses UDP echo packets instead of ICMP.
Detailed technical explanation
How to think about this question
The Smurf attack leverages directed broadcast addresses (e.g., 10.0.0.255) which, in older network configurations, would forward the ICMP echo request to every host in the subnet. Each host then replies to the spoofed source IP, creating amplification. Modern routers disable directed broadcast forwarding by default (as per RFC 2644), but the attack can still be attempted on misconfigured networks or via IPv6 multicast abuse. The amplification factor can be as high as the number of hosts in the broadcast domain.
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.
What to study next
Got this wrong? Here's your next step.
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FAQ
Questions learners often ask
What does this N10-009 question test?
Network Security — This question tests Network Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Smurf attack — A Smurf attack exploits IP broadcast addressing and ICMP. The attacker sends a large number of ICMP echo request packets with a spoofed source IP (the victim's IP) to a network's broadcast address. All hosts on that network then send ICMP echo reply packets to the victim, overwhelming it with traffic. Since the server never sent any echo requests, the unsolicited flood of echo replies is the hallmark of a Smurf attack.
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: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Last reviewed: Jun 11, 2026
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.
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