The correct answer is to add a new allow rule above the deny rule that matches the specific traffic. This works because Palo Alto Networks security policies are evaluated in sequential order from top to bottom, and the first matching rule is applied; by placing a specific allow rule for the critical application’s source IP range above a general deny-all rule, the allowed traffic is permitted before it can be blocked. On the PCNSA exam, this concept tests your understanding of rule order and exception-based policy design, often appearing in scenarios where you must permit specific inter-zone traffic while maintaining a default-deny posture. A common trap is trying to modify the deny rule itself or create a single rule with conflicting actions, which is not supported. Remember the memory tip: “Specific before general, allow before deny” to ensure your exceptions work correctly.
PCNSA Securing Traffic Practice Question
This PCNSA practice question tests your understanding of securing traffic. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
Traffic between two internal zones is being dropped due to a security policy rule that blocks any traffic. However, the administrator needs to allow specific inter-zone traffic for a critical application. The allowed traffic is sourced from a special IP range. How should the administrator configure the security policy to permit only this traffic while still blocking other traffic?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Add a new allow rule above the deny rule that matches the specific traffic.
Option B is correct because a deny rule with an exception can be implemented by placing a specific allow rule before a general deny rule. Option A is wrong because modifying the deny rule to allow would permit all. Option C is wrong because a single rule with allow and deny is not possible. Option D is wrong because creating a separate zone is unnecessary.
Key principle: ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
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 a single rule with both allow and deny actions based on source.
Why it's wrong here
A rule has one action; you cannot have both allow and deny in one rule.
✗
Place the specific servers in a different zone and create a new policy for that zone.
Why it's wrong here
This complicates design unnecessarily.
✓
Add a new allow rule above the deny rule that matches the specific traffic.
Why this is correct
The allow rule will be evaluated first and permit the traffic before reaching the deny rule.
Related concept
Standard ACLs match source addresses.
✗
Modify the existing deny rule to allow all traffic.
Why it's wrong here
This would allow all traffic, not just the specific application.
Common exam traps
Common exam trap: ACLs stop at the first match
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Detailed technical explanation
How to think about this question
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
KKey Concepts to Remember
Standard ACLs match source addresses.
Extended ACLs can match source, destination, protocol and ports.
The first matching ACL entry is used.
There is usually an implicit deny at the end.
TExam Day Tips
→Check inbound versus outbound direction.
→Read the ACL from top to bottom.
→Look for a broader permit or deny above the intended line.
Key takeaway
ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
Real-world example
How this comes up in practice
A security administrator must allow nursing staff to reach a patient records server while blocking access from the guest Wi-Fi VLAN. After applying an extended ACL, traffic is still blocked from nursing workstations. The ACL was applied outbound instead of inbound on the wrong interface. Questions like this test ACL direction and placement rules.
What to study next
Got this wrong? Here's your next step.
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related PCNSA ACL questions on filtering logic and placement.
Securing Traffic — This question tests Securing Traffic — Standard ACLs match source addresses..
What is the correct answer to this question?
The correct answer is: Add a new allow rule above the deny rule that matches the specific traffic. — Option B is correct because a deny rule with an exception can be implemented by placing a specific allow rule before a general deny rule. Option A is wrong because modifying the deny rule to allow would permit all. Option C is wrong because a single rule with allow and deny is not possible. Option D is wrong because creating a separate zone is unnecessary.
What should I do if I get this PCNSA question wrong?
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related PCNSA ACL questions on filtering logic and placement.
What is the key concept behind this question?
Standard ACLs match source addresses.
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.