PCNSE Securing Traffic and App-ID Practice Question
During a security audit, it is discovered that a custom application signature matches too broadly, causing benign traffic to be classified as the custom app. What change should be made to narrow the signature?
⚠ Common exam trap
The trap here is that candidates mistakenly think expanding port ranges or removing protocol fields will narrow the signature, when in fact those actions broaden the match criteria and worsen false positives.
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
✓
Add a data pattern filter to match a specific payload signature.
Adding a data pattern filter allows the custom App-ID signature to match on a specific payload string or byte sequence, which narrows the scope of traffic classified as that application. Without a data pattern, the signature may rely solely on IP protocol, port, or other broad criteria, causing false positives. By requiring a unique payload signature, only traffic containing that exact data pattern is identified as the custom application.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Remove the protocol field from the signature.
Why it's wrong here
Removing protocol would make matching less specific.
- ✗
Use a wider port range and remove data patterns.
Why it's wrong here
This would increase the match scope.
- ✓
Add a data pattern filter to match a specific payload signature.
Why this is correct
Data patterns narrow matching to specific traffic characteristics.
- ✗
Expand the port range to include more traffic.
Why it's wrong here
Expanding range would match more traffic, not less.
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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.