The answer is the `-sn` option, which performs a ping sweep. This is the fastest Nmap host discovery method because it sends only lightweight probes—ICMP echo requests, TCP SYN to port 443, TCP ACK to port 80, and ICMP timestamp requests—to determine if a host is alive without conducting any port scanning. On a large internal network, skipping the service enumeration phase dramatically reduces scan time, making `-sn` ideal for initial reconnaissance. For the CompTIA PenTest+ PT0-002 exam, this question tests your understanding of efficiency versus thoroughness; a common trap is choosing `-T5` (timing template) instead, which only speeds up a full port scan but still scans ports. Remember the memory tip: “Sniff for life, skip the strife”—the `-sn` flag sniffs for live hosts and avoids the strife of port scanning, giving you the fastest possible sweep.
PT0-002 Tools and Code Analysis Practice Question
This PT0-002 practice question tests your understanding of tools and code analysis. 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 penetration tester wants to identify live hosts on a large internal network. Which Nmap option would be the FASTEST for initial host discovery?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
-sn (Ping sweep)
The -sn option performs a ping sweep, sending ICMP echo requests, TCP SYN to port 443, TCP ACK to port 80, and ICMP timestamp requests by default. It does not perform port scanning, making it the fastest method for initial host discovery on a large internal network because it only checks for host availability without enumerating services.
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.
✗
-sV (Version detection)
Why it's wrong here
Version detection probes open ports to determine service versions, which is slower than a simple host discovery.
✗
-sS (SYN stealth scan)
Why it's wrong here
SYN scan is a port scanning technique; it scans ports on each host, which is more time-consuming than a ping sweep.
✓
-sn (Ping sweep)
Why this is correct
The -sn option uses minimal probes to determine host availability and is the fastest method for host discovery.
Related concept
Read the scenario before looking for a memorised answer.
✗
-A (Aggressive scan)
Why it's wrong here
Aggressive scan enables OS detection, version detection, script scanning, and traceroute, making it much slower.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse host discovery with port scanning, assuming that a SYN scan (-sS) is the fastest because it is stealthy, but they overlook that -sn is designed specifically for host discovery and avoids the overhead of port scanning entirely.
Detailed technical explanation
How to think about this question
Under the hood, Nmap's -sn option uses a combination of ICMP echo requests, TCP SYN to port 443, TCP ACK to port 80, and ICMP timestamp requests to determine if a host is up. In a large internal network, this can be further optimized by using the -PE (ICMP echo), -PP (ICMP timestamp), or -PM (ICMP netmask) options to customize the probe types, and the -n option to skip DNS resolution for even faster results. Real-world scenarios often involve firewalls that block ICMP, so Nmap's fallback to TCP probes ensures discovery even in restrictive environments.
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 team runs a vulnerability scan on a web application and discovers an unpatched SQL injection flaw. The team prioritises remediation by CVSS score — critical flaws are patched within 24 hours, high within 7 days. Questions like this test whether you understand vulnerability management processes, scanning tools, and remediation prioritisation.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this PT0-002 question in full detail.
Tools and Code Analysis — This question tests Tools and Code Analysis — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: -sn (Ping sweep) — The -sn option performs a ping sweep, sending ICMP echo requests, TCP SYN to port 443, TCP ACK to port 80, and ICMP timestamp requests by default. It does not perform port scanning, making it the fastest method for initial host discovery on a large internal network because it only checks for host availability without enumerating services.
What should I do if I get this PT0-002 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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 PT0-002 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 PT0-002 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.