- A
A) SYN flood
Correct. A SYN flood is a DoS attack that sends numerous SYN packets, leaving half-open connections and consuming server resources.
- B
B) Smurf attack
Why wrong: Incorrect. A Smurf attack uses ICMP echo requests to a broadcast address, causing all hosts to reply to the victim. It does not involve TCP SYN packets.
- C
C) Ping of death
Why wrong: Incorrect. A Ping of death sends an oversized ICMP packet that causes a buffer overflow. It does not use TCP SYN packets.
- D
D) ARP poisoning
Why wrong: Incorrect. ARP poisoning involves sending fake ARP replies to intercept traffic, not sending TCP SYN packets to a server.
Question 206 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 the company's web server is receiving a high volume of TCP SYN packets from a single source IP address, but the server is not completing the three-way handshake. 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
✓
A) SYN flood
A SYN flood attack exploits the TCP three-way handshake by sending a high volume of SYN packets from a spoofed or single source IP without completing the handshake. The server allocates resources for each half-open connection, eventually exhausting its connection table and denying service to legitimate users. This matches the scenario where the server receives many SYN packets but never completes the handshake.
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.
- ✓
A) SYN flood
Why this is correct
Correct. A SYN flood is a DoS attack that sends numerous SYN packets, leaving half-open connections and consuming server resources.
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.
- ✗
B) Smurf attack
Why it's wrong here
Incorrect. A Smurf attack uses ICMP echo requests to a broadcast address, causing all hosts to reply to the victim. It does not involve TCP SYN packets.
When this WOULD be correct
A Smurf attack would be correct if the question described a high volume of ICMP echo reply packets (or ping replies) overwhelming a target, or if the attack involved sending ICMP echo requests to a network broadcast address with a spoofed source IP.
- ✗
C) Ping of death
Why it's wrong here
Incorrect. A Ping of death sends an oversized ICMP packet that causes a buffer overflow. It does not use TCP SYN packets.
When this WOULD be correct
This option would be correct in a question describing a server crashing or becoming unresponsive after receiving a single oversized ICMP echo request packet, or a series of fragmented ICMP packets that reassemble into a packet larger than 65535 bytes.
- ✗
D) ARP poisoning
Why it's wrong here
Incorrect. ARP poisoning involves sending fake ARP replies to intercept traffic, not sending TCP SYN packets to a server.
When this WOULD be correct
An exam question describing an attacker sending forged ARP replies to associate their MAC address with the default gateway's IP, causing traffic to be redirected to the attacker, would make ARP poisoning the correct answer.
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.
✓A) SYN floodCorrect answer▾
Why this is correct
Correct. A SYN flood is a DoS attack that sends numerous SYN packets, leaving half-open connections and consuming server resources.
✗B) Smurf attackWrong answer — click to see why▾
Why this is wrong here
A Smurf attack uses ICMP echo requests (pings) to a broadcast address, causing all hosts on the network to reply to a spoofed victim IP, overwhelming it with ICMP replies, not TCP SYN packets.
★ When this WOULD be the correct answer
A Smurf attack would be correct if the question described a high volume of ICMP echo reply packets (or ping replies) overwhelming a target, or if the attack involved sending ICMP echo requests to a network broadcast address with a spoofed source IP.
Why candidates choose this
Candidates may confuse any high-volume network attack with a Smurf attack, or they might think 'SYN flood' is too obvious and second-guess themselves, choosing a less familiar term.
✗C) Ping of deathWrong answer — click to see why▾
Why this is wrong here
A ping of death attack involves sending oversized or malformed ICMP packets to crash a system, not a high volume of TCP SYN packets that fail to complete the three-way handshake.
★ When this WOULD be the correct answer
This option would be correct in a question describing a server crashing or becoming unresponsive after receiving a single oversized ICMP echo request packet, or a series of fragmented ICMP packets that reassemble into a packet larger than 65535 bytes.
Why candidates choose this
Candidates may confuse any attack that overwhelms a server with 'ping of death' because both involve network flooding, but they fail to distinguish between ICMP-based attacks and TCP SYN floods.
✗D) ARP poisoningWrong answer — click to see why▾
Why this is wrong here
ARP poisoning manipulates the ARP cache to intercept traffic on a local network, not to flood a web server with TCP SYN packets from a single source.
★ When this WOULD be the correct answer
An exam question describing an attacker sending forged ARP replies to associate their MAC address with the default gateway's IP, causing traffic to be redirected to the attacker, would make ARP poisoning the correct answer.
Why candidates choose this
Candidates may confuse network-layer attacks (ARP poisoning) with transport-layer attacks (SYN flood) due to a lack of understanding of the TCP/IP model layers.
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
CompTIA often tests the distinction between a SYN flood and a Smurf attack by describing a flood of packets from a single source—candidates confuse the ICMP-based Smurf attack with the TCP-based SYN flood because both involve flooding, but the protocol and mechanism are completely different.
Detailed technical explanation
How to think about this question
In a SYN flood, the attacker sends SYN packets with a spoofed source IP (often unroutable or non-existent) so the server's SYN-ACK responses go unanswered, leaving connections in a half-open state. The server's backlog queue (e.g., net.core.somaxconn in Linux) fills up, and once full, new legitimate SYN packets are dropped. Modern mitigations include SYN cookies (RFC 4987), which encode connection state in the SYN-ACK sequence number, avoiding resource allocation until the handshake completes.
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 security administrator must allow nursing staff to reach a patient records server while blocking access from the guest Wi-Fi VLAN. After applying an extended ACL, traffic is still blocked from nursing workstations. The ACL was applied outbound instead of inbound on the wrong interface. Questions like this test ACL direction and placement rules.
Visual reference
What to study next
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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: A) SYN flood — A SYN flood attack exploits the TCP three-way handshake by sending a high volume of SYN packets from a spoofed or single source IP without completing the handshake. The server allocates resources for each half-open connection, eventually exhausting its connection table and denying service to legitimate users. This matches the scenario where the server receives many SYN packets but never completes the handshake.
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
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 →
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Last reviewed: Jun 30, 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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