- A
Configure User-ID and enable User-ID mapping for the web traffic.
Why wrong: User-ID is for identifying users, not for application classification. It would not resolve the misidentification.
- B
Review the App-ID logs for the traffic to see if the application is being identified as 'incomplete' or 'not-applicable', and ensure the firewall can successfully decode the traffic. If needed, enable SSL decryption or update the SSL/TLS certificate chain on the firewall.
App-ID may fail to decode the traffic if the SSL handshake fails or the certificate is not trusted. This leads to 'unknown-tcp' classification. Enabling SSL decryption or ensuring proper certificate chains can resolve this.
- C
Disable all application security profiles for the affected traffic to allow the firewall to classify based on port only.
Why wrong: Disabling security profiles does not affect application identification; it only reduces inspection. It would not fix the classification issue.
- D
Create custom App-ID signatures for the web servers.
Why wrong: Custom App-IDs are not needed for standard web traffic; the built-in signatures should work.
Quick Answer
The answer is to review the App-ID logs for an 'incomplete' or 'not-applicable' status and consider enabling SSL decryption. This is correct because without SSL decryption, the firewall sees only encrypted payloads; while the TCP handshake may be recognized, the application payload remains opaque, causing App-ID to fail and default to 'unknown-tcp' for HTTPS traffic that cannot be fully decoded. On the PCNSA exam, this scenario tests your understanding of how App-ID processes the first few packets of a session—if the application signature is not matched within those packets, the traffic falls through to a catch-all rule. A common trap is assuming that 'ssl' or 'web-browsing' will always be identified from the handshake alone, but encrypted traffic requires decryption for deep inspection. Remember the memory tip: "No decrypt, no detect—if the payload is hidden, App-ID is forbidden."
PCNSA App-ID and Content-ID Practice Question
This PCNSA practice question tests your understanding of app-id and content-id. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 network security engineer at a large enterprise is troubleshooting an issue where web traffic (HTTP and HTTPS) from the corporate LAN to the internet is being incorrectly classified by the Palo Alto Networks firewall. The firewall is running PAN-OS 10.2. The security policy has an App-ID based rule that allows 'web-browsing' and 'ssl' applications to the internet. However, legitimate web traffic is being blocked by a different rule that denies 'unknown-tcp' traffic. The engineer has verified that the firewall has internet connectivity and that the SSL decryption is not configured. The engineer also confirmed that the application override is not configured for any of the affected IPs. What is the most likely reason for the misclassification, and what action should the engineer take to resolve the issue?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"most likely"Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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
Review the App-ID logs for the traffic to see if the application is being identified as 'incomplete' or 'not-applicable', and ensure the firewall can successfully decode the traffic. If needed, enable SSL decryption or update the SSL/TLS certificate chain on the firewall.
Option B is correct because the firewall's App-ID relies on decoding the initial packets of a session to identify the application. Without SSL decryption, HTTPS traffic appears as encrypted payload, which App-ID cannot decode, often resulting in classification as 'ssl' (if the handshake is recognized) or 'unknown-tcp' if the handshake is incomplete or not fully parsed. The engineer should review the App-ID logs for 'incomplete' or 'not-applicable' status, and enabling SSL decryption or updating the certificate chain would allow the firewall to inspect the encrypted traffic and correctly identify it as 'web-browsing' or 'ssl'.
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.
- ✗
Configure User-ID and enable User-ID mapping for the web traffic.
Why it's wrong here
User-ID is for identifying users, not for application classification. It would not resolve the misidentification.
- ✓
Review the App-ID logs for the traffic to see if the application is being identified as 'incomplete' or 'not-applicable', and ensure the firewall can successfully decode the traffic. If needed, enable SSL decryption or update the SSL/TLS certificate chain on the firewall.
Why this is correct
App-ID may fail to decode the traffic if the SSL handshake fails or the certificate is not trusted. This leads to 'unknown-tcp' classification. Enabling SSL decryption or ensuring proper certificate chains can resolve this.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Disable all application security profiles for the affected traffic to allow the firewall to classify based on port only.
Why it's wrong here
Disabling security profiles does not affect application identification; it only reduces inspection. It would not fix the classification issue.
- ✗
Create custom App-ID signatures for the web servers.
Why it's wrong here
Custom App-IDs are not needed for standard web traffic; the built-in signatures should work.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume App-ID can always identify HTTPS traffic as 'ssl' without decryption, but they overlook that incomplete handshakes or missing initial packets cause the firewall to classify the traffic as 'unknown-tcp', leading to incorrect rule matches.
Detailed technical explanation
How to think about this question
App-ID in PAN-OS uses a multi-pass approach: it first identifies the application by protocol decoding, then uses SSL/TLS handshake analysis to identify 'ssl' even without decryption, but if the handshake is incomplete (e.g., due to TCP segmentation or asymmetric routing), the traffic may fall back to 'unknown-tcp'. The 'incomplete' status in the App-ID logs indicates that the firewall could not see the full handshake, often because the first few packets were not received or the session was already established before the firewall inspected it.
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 small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
App-ID and Content-ID — study guide chapter
Learn the concepts, then practise the questions
- →
App-ID and Content-ID practice questions
Targeted practice on this topic area only
- →
All PCNSA questions
524 questions across all exam domains
- →
Palo Alto Networks Certified Network Security Administrator PCNSA study guide
Full concept coverage aligned to exam objectives
- →
PCNSA practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PCNSA practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Managing Objects practice questions
Practise PCNSA questions linked to Managing Objects.
Policy Evaluation and Management practice questions
Practise PCNSA questions linked to Policy Evaluation and Management.
Securing Traffic practice questions
Practise PCNSA questions linked to Securing Traffic.
Core Concepts practice questions
Practise PCNSA questions linked to Core Concepts.
Palo Alto Networks Platforms and Architecture practice questions
Practise PCNSA questions linked to Palo Alto Networks Platforms and Architecture.
Device Management and Services practice questions
Practise PCNSA questions linked to Device Management and Services.
App-ID and Content-ID practice questions
Practise PCNSA questions linked to App-ID and Content-ID.
Decryption and Monitoring practice questions
Practise PCNSA questions linked to Decryption and Monitoring.
PCNSA fundamentals practice questions
Practise PCNSA questions linked to PCNSA fundamentals.
PCNSA scenario practice questions
Practise PCNSA questions linked to PCNSA scenario.
PCNSA troubleshooting practice questions
Practise PCNSA questions linked to PCNSA troubleshooting.
Practice this exam
Start a free PCNSA practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this PCNSA question test?
App-ID and Content-ID — This question tests App-ID and Content-ID — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Review the App-ID logs for the traffic to see if the application is being identified as 'incomplete' or 'not-applicable', and ensure the firewall can successfully decode the traffic. If needed, enable SSL decryption or update the SSL/TLS certificate chain on the firewall. — Option B is correct because the firewall's App-ID relies on decoding the initial packets of a session to identify the application. Without SSL decryption, HTTPS traffic appears as encrypted payload, which App-ID cannot decode, often resulting in classification as 'ssl' (if the handshake is recognized) or 'unknown-tcp' if the handshake is incomplete or not fully parsed. The engineer should review the App-ID logs for 'incomplete' or 'not-applicable' status, and enabling SSL decryption or updating the certificate chain would allow the firewall to inspect the encrypted traffic and correctly identify it as 'web-browsing' or 'ssl'.
What should I do if I get this PCNSA question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
Last reviewed: Jun 25, 2026
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.
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.