The correct answer is that the traffic will be denied by the implicit deny rule because the application does not match. This occurs because the security rule explicitly specifies the application 'ssl' for HTTPS traffic, but the user’s session is being classified by App-ID as a different application—such as 'web-browsing'—due to a security rule application mismatch. On the Palo Alto Networks firewall, App-ID identifies the actual application regardless of the port number, so even though TCP 443 is used, the rule’s application condition must match exactly; if it does not, the traffic falls through to the implicit deny at the end of the rulebase. On the PCNSA exam, this scenario tests your understanding that application-based rules override port-based assumptions, and a common trap is assuming that matching the port alone is sufficient. Remember the memory tip: “Port is a hint, App-ID is the rule—mismatch means deny.”
PCNSA Palo Alto Networks Platforms and Architecture Practice Question
This PCNSA practice question tests your understanding of palo alto networks platforms and architecture. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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.
Exhibit
Refer to the exhibit.
config
security {
rules {
rule allow-http {
source-zone [ trust ];
destination-zone [ untrust ];
source-address [ any ];
destination-address [ any ];
application [ web-browsing ];
service [ application-default ];
action allow;
log-start yes;
}
}
}
Based on the exhibit, what will happen when a user in the trust zone attempts to access an HTTPS website (TCP 443)?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The traffic will be denied by the implicit deny rule because the application does not match.
Option D is correct because the security rule shown in the exhibit specifies the application as 'ssl' (HTTPS), but the user is attempting to access an HTTPS website using TCP 443. However, the rule's application match is likely set to a different application or the traffic is being classified as 'web-browsing' or another application that does not match the rule's application condition. Since no rule explicitly permits the traffic, the implicit deny rule at the end of the rulebase will block it. Palo Alto Networks firewalls use App-ID to identify applications regardless of port, so even if TCP 443 is used, the application must match exactly for the rule to apply.
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.
✗
The traffic will be allowed if the user uses HTTP instead.
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume that because the source and destination zones match and the port is standard (TCP 443), the rule will permit the traffic, but they overlook the critical requirement that the application must also match the rule's application condition.
Detailed technical explanation
How to think about this question
Palo Alto Networks firewalls use App-ID to identify applications by analyzing traffic patterns, not just port numbers. Even if traffic uses TCP 443, it could be classified as 'web-browsing' (HTTP over SSL) or 'ssl' depending on the content. The implicit deny rule is a default security rule at the end of the rulebase that denies all traffic not explicitly permitted, and it is always present unless overridden. In real-world scenarios, misconfigured application matching is a common cause of unexpected denials, especially when using non-standard ports or applications like custom HTTPS services.
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.
Palo Alto Networks Platforms and Architecture — This question tests Palo Alto Networks Platforms and Architecture — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The traffic will be denied by the implicit deny rule because the application does not match. — Option D is correct because the security rule shown in the exhibit specifies the application as 'ssl' (HTTPS), but the user is attempting to access an HTTPS website using TCP 443. However, the rule's application match is likely set to a different application or the traffic is being classified as 'web-browsing' or another application that does not match the rule's application condition. Since no rule explicitly permits the traffic, the implicit deny rule at the end of the rulebase will block it. Palo Alto Networks firewalls use App-ID to identify applications regardless of port, so even if TCP 443 is used, the application must match exactly for the rule to apply.
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.
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 →
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.
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.