Question 361 of 524
Decryption and MonitoringhardMultiple ChoiceObjective-mapped

Quick Answer

The answer is to scope the inbound decryption rule exclusively to traffic from external sources. This resolves the double decryption issue because when an internal client sends traffic to an internal server, the inbound decryption rule should not apply—only outbound decryption should handle the server’s subsequent external connections. By restricting the inbound rule’s source zone to Untrust (or an equivalent external zone), internal-to-internal traffic bypasses inbound decryption entirely, preventing the performance-draining loop and certificate warnings. On the PCNSA exam, this scenario tests your understanding of decryption policy ordering and zone-based scoping, a common trap being the assumption that inbound decryption always applies to all traffic destined for internal servers. Remember the memory tip: “Inbound for inbound traffic only—keep internal flows out of the inbound rule.”

PCNSA Decryption and Monitoring Practice Question

This PCNSA practice question tests your understanding of decryption and monitoring. 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 company has a Palo Alto firewall with both inbound and outbound decryption. The security team notices that some traffic to a specific internal server is being double-decrypted: first by inbound decryption when the client is internal, and second by outbound decryption when the server initiates connections to external resources. This causes performance issues and certificate warnings. The firewall policy has separate rules for inbound and outbound decryption, and all internal traffic passes through the firewall. How should the administrator resolve this?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "first"

    Why it matters: Order matters here. You are being tested on which action comes before the others — not which action is generally useful.

Question 1hardmultiple choice
Full question →

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

Ensure that the inbound decryption rule only applies to traffic from external sources, not internal.

The core issue is that inbound decryption is incorrectly applied to traffic from internal clients to the internal server, causing double decryption when the server subsequently initiates outbound connections. By ensuring the inbound decryption rule only applies to traffic from external sources (i.e., source zone is untrust), internal-to-internal traffic bypasses inbound decryption, eliminating the double-decryption loop. This aligns with best practices where inbound decryption is scoped to traffic originating outside the network.

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.

  • Create a decryption exclusion rule for traffic between internal clients and the internal server.

    Why it's wrong here

    Excluding this traffic from all decryption would remove security visibility.

  • Ensure that the inbound decryption rule only applies to traffic from external sources, not internal.

    Why this is correct

    By restricting the source zone to Untrust, internal clients will not be subject to inbound decryption, eliminating double decryption.

    Clue confirmation

    The clue word "first" in the question point toward this answer.

    Related concept

    Read the scenario before looking for a memorised answer.

  • Disable outbound decryption for the subnet of the internal server.

    Why it's wrong here

    This would stop outbound decryption for the server, but the server's outbound traffic may need inspection.

  • Use a no-decrypt rule for traffic from the internal server's IP to the internet.

    Why it's wrong here

    This only addresses outbound decryption, not the inbound decryption applied to internal clients.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates may focus on excluding specific traffic (options A, C, D) rather than correcting the zone-based scope of the inbound decryption rule, which is the fundamental cause of the double-decryption problem.

Detailed technical explanation

How to think about this question

Under the hood, Palo Alto firewalls process decryption in a specific order: inbound decryption rules are evaluated first for traffic entering the firewall, and outbound decryption rules are applied to traffic leaving. When an internal client connects to an internal server, if the inbound decryption rule does not restrict the source zone (e.g., it matches any zone), the traffic is decrypted, and then when the server initiates outbound connections, the outbound decryption rule decrypts again, causing performance hits and certificate chain issues. In a real-world scenario, this often occurs when administrators use broad source zone matching (e.g., 'any') instead of explicitly limiting inbound decryption to the 'untrust' zone.

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.

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Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

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FAQ

Questions learners often ask

What does this PCNSA question test?

Decryption and Monitoring — This question tests Decryption and Monitoring — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Ensure that the inbound decryption rule only applies to traffic from external sources, not internal. — The core issue is that inbound decryption is incorrectly applied to traffic from internal clients to the internal server, causing double decryption when the server subsequently initiates outbound connections. By ensuring the inbound decryption rule only applies to traffic from external sources (i.e., source zone is untrust), internal-to-internal traffic bypasses inbound decryption, eliminating the double-decryption loop. This aligns with best practices where inbound decryption is scoped to traffic originating outside the network.

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: "first". Order matters here. You are being tested on which action comes before the others — not which action is generally useful.

What is the key concept behind this question?

Read the scenario before looking for a memorised answer.

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Last reviewed: Jun 25, 2026

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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.