PCNSA App-ID and Content-ID Practice Question
A network administrator observes that a user is able to access a cloud storage application even though a security rule explicitly blocks that application. Other application blocks work correctly. What is the most likely cause?
⚠ Common exam trap
It's easy for candidates to assume a security rule blocking an application will always work, but they overlook the fact that App-ID must first correctly identify the application—especially when traffic is encrypted over standard ports—and that without SSL decryption, the firewall may see only 'web-browsing' or 'ssl' instead of the specific cloud storage app.
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
✓
The user is accessing the application over HTTPS on a common web port, and App-ID cannot correctly identify the application.
App-ID relies on multiple identification mechanisms, including protocol decoding, application signatures, and SSL decryption. When a cloud storage application is accessed over HTTPS on a common web port (e.g., 443), App-ID may fail to correctly identify the application if the traffic is encrypted and no SSL decryption policy is applied, or if the application uses a technique like 'port hopping' or 'tunneling over HTTP/HTTPS'. This causes the security rule explicitly blocking the application to be ineffective, as the traffic is instead matched against a different application signature (e.g., 'web-browsing') that is allowed.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The user is accessing the application over HTTPS on a common web port, and App-ID cannot correctly identify the application.
Why this is correct
App-ID may misidentify the traffic as generic web-browsing if it cannot discern the specific application.
- ✗
The security rule order is incorrect; a previous rule allows the application.
Why it's wrong here
Rule order could cause unintended allows, but the scenario suggests explicit block not working.
- ✗
URL filtering is misconfigured and allowing the URL for the cloud storage.
Why it's wrong here
URL filtering and App-ID are separate; application blocks take precedence.
- ✗
A Content-ID profile is overriding the application block.
Why it's wrong here
Content-ID profiles do not override application blocks.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCNSA 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 PCNSA exam.