CPENT Network And Perimeter Exploitation Practice Question
A penetration tester is analyzing a network where ICMP echo requests are blocked by perimeter firewalls, making traditional host discovery fail. Which Nmap host discovery option should be used to discover live hosts using TCP ACK packets sent to port 80?
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
✓
-PA80
The -PA flag in Nmap specifies a TCP ACK probe to determine if hosts are alive, as port 80 is frequently allowed through corporate firewalls.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
-PS80
Why it's wrong here
-PS uses a TCP SYN probe.
- ✓
-PA80
Why this is correct
-PA uses a TCP ACK probe targeting the specified port.
- ✗
-PE
Why it's wrong here
-PE uses ICMP echo requests, which are blocked in this scenario.
- ✗
-PU80
Why it's wrong here
-PU uses a UDP probe.
About these practice questions
One of 274 original CPENT practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official EC-Council exam blueprint
This CPENT 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 CPENT exam.