PCNSE Securing Traffic and App-ID Practice Question
An engineer wants to block the use of file-sharing application BitTorrent, but allow file transfers over SFTP which also uses port 22. What is the most effective way to achieve this using App-ID?
⚠ Common exam trap
Candidates often assume port-based rules are sufficient, but App-ID is designed to identify applications by their unique signatures, not ports, so a port-based approach (like an application override) would fail to block BitTorrent if it uses the same port as SFTP.
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
✓
Create a security rule that denies application 'bittorrent' and allows application 'sftp'.
D is correct because App-ID identifies applications by their unique signatures, not just ports. By creating a security rule that denies 'bittorrent' and allows 'sftp', the firewall can block BitTorrent traffic even if it uses non-standard ports, while permitting SFTP on port 22 based on its distinct application signature.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Create an application filter that matches sftp.
Why it's wrong here
Application filters are used for grouping, not for blocking/allowing traffic.
- ✗
Use QoS to limit BitTorrent traffic.
Why it's wrong here
QoS limits bandwidth but does not block the application.
- ✗
Use an application override to classify all port 22 traffic as sftp.
Why it's wrong here
This would misclassify BitTorrent traffic as sftp, bypassing the block.
- ✓
Create a security rule that denies application 'bittorrent' and allows application 'sftp'.
Why this is correct
Correct: This uses App-ID to differentiate and apply appropriate actions per application.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCNSE practice question is part of Courseiva's free Palo Alto Networks 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 PCNSE exam.