CEH Footprinting, Reconnaissance and Scanning Practice Question
A penetration tester runs the following command: masscan 10.0.0.0/24 -p80,443,8080 --rate=10000. Compared to Nmap, what is the PRIMARY advantage of using Masscan for this scan?
⚠ Common exam trap
EC-Council often tests the misconception that Masscan is stealthier than Nmap, but in reality, its high packet rate makes it more detectable, and the trap here is that candidates confuse speed with stealth.
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
✓
Masscan can scan a large number of hosts and ports at very high speed
Masscan is designed for asynchronous, high-speed scanning, capable of transmitting packets at rates exceeding 10 million packets per second. In this command, the `--rate=10000` parameter sets a transmission rate of 10,000 packets per second, allowing it to scan the entire 10.0.0.0/24 subnet (256 hosts) for three ports in a fraction of the time Nmap would require. Nmap, while feature-rich, operates synchronously by default and cannot match Masscan's raw packet throughput for large-scale port scanning.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Masscan can scan a large number of hosts and ports at very high speed
Why this is correct
Masscan is specifically engineered for high-performance, asynchronous SYN scanning across vast IP ranges. Its custom TCP/IP stack allows it to send SYN packets and process SYN-ACK responses at rates exceeding millions of packets per second, far surpassing traditional scanners. This design enables rapid discovery of open ports across entire internet segments or all 65,535 ports on numerous targets, making it ideal for large-scale reconnaissance.
- ✗
Masscan provides more detailed service version detection than Nmap
Why it's wrong here
Masscan is primarily a port scanner designed for speed, focusing on identifying open TCP/UDP ports by sending SYN packets and processing responses at the network layer. It does not incorporate application-layer fingerprinting or service version detection capabilities, which are complex and time-consuming processes. In contrast, Nmap's -sV option actively probes open ports to determine the exact service and version running, a feature Masscan explicitly omits to maintain its high throughput.
- ✗
Masscan is stealthier than Nmap and less likely to be detected
Why it's wrong here
Masscan’s high-speed asynchronous SYN scanning sacrifices stealth for throughput; at a rate of 10,000 packets per second against a /24 subnet, it will generate far more conspicuous traffic than Nmap’s default timing controls, making detection *more* likely, not less. This option is tempting because Masscan is often used for rapid internet-wide reconnaissance where stealth is irrelevant, and in a low-rate, single-port scan it could evade basic logging, but the aggressive rate in this command directly contradicts any stealth advantage.
- ✗
Masscan can scan all 65535 ports faster than Nmap
Why it's wrong here
While Masscan is indeed capable of scanning all 65,535 TCP ports across a target range significantly faster than Nmap due to its asynchronous design, the statement is not universally true for *any* Masscan command. The specific command `masscan 10` is incomplete, but if interpreted as scanning a target with default settings, Masscan typically scans a predefined list of common ports (e.g., 1000 most common), not all 65,535 ports by default. Therefore, while Masscan *can* achieve this speed for a full port scan, the provided command does not explicitly trigger such a comprehensive scan.
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Related to this question
Learn chapter
Scanning Networks
Key term
Port Scanning Techniques
Port scanning techniques are methods used to probe a computer or network to discover which network ports are open and which services are running on those ports.
Key term
Active reconnaissance
Active reconnaissance is the process of directly interacting with a target system or network to gather information, often through scanning and probing.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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