The answer is a Smurf attack. This is correct because a Smurf attack exploits IP broadcast addressing by sending ICMP Echo Request packets to a network’s broadcast address with the victim’s IP address spoofed as the source. Every active host on that network then replies with an ICMP Echo Reply to the victim, overwhelming it with traffic and causing a denial of service. On the Certified Ethical Hacker CEH exam, this scenario tests your understanding of amplification-based DDoS attacks and the misuse of ICMP protocols. A common trap is confusing it with a ping flood, which targets a single host directly rather than using a broadcast amplifier. The key differentiator is the single destination IP receiving a flood of Echo Replies from multiple sources. Memory tip: think “Smurf sends the request to everyone, but the replies all land on one poor victim.”
CEH Practice Question: Malware, Social Engineering and Network Attacks
This CEH practice question tests your understanding of malware, social engineering and network attacks. 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 a high volume of ICMP Echo Reply packets on the network. The source IPs are varied, but the destination IP is the same. 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 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 sends ICMP Echo Request packets to a network broadcast address with a spoofed source IP (the target). All hosts on the network reply to the target, flooding it with ICMP Echo Replies.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
UDP flood
Why it's wrong here
UDP flood sends many UDP packets to random ports, not ICMP packets.
✗
Ping of Death
Why it's wrong here
Ping of Death sends oversized ICMP packets to cause a buffer overflow, not a flood of replies.
✓
Smurf attack
Why this is correct
Correct. The large number of ICMP Echo Replies from multiple sources to a single target is characteristic of a Smurf attack.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
An ICMP flood typically sends many ICMP Echo Requests (not replies) from a single source to overwhelm the target.
Common exam traps
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CEH question in full detail.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related CEH subnetting questions on CIDR, address ranges, and subnet selection.
Malware, Social Engineering and Network Attacks — This question tests Malware, Social Engineering and Network Attacks — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Smurf attack — A Smurf attack sends ICMP Echo Request packets to a network broadcast address with a spoofed source IP (the target). All hosts on the network reply to the target, flooding it with ICMP Echo Replies.
What should I do if I get this CEH question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related CEH subnetting questions on CIDR, address ranges, and subnet selection.
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?
CIDR notation defines the prefix length.
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 CEH practice question is part of Courseiva's free EC-Council 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 CEH 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.