← PCNSA·Palo Alto Networks

Question 497 of 524

Policy Evaluation and Management →hardMultiple ChoiceObjective-mapped

Quick Answer

The answer is a virtual router mismatch, where the new subnet 10.10.20.0/24 is routed through a different virtual router than the one associated with the Internal zone’s interface. This occurs because Palo Alto Networks firewalls enforce zone-based security policies at the ingress interface, and each interface belongs to a specific virtual router. If a more specific route for the new subnet points to a different virtual router, traffic from that subnet ingresses via an interface in a different zone, causing the SSH rule to never match. On the PCNSA exam, this tests your understanding of how virtual routers affect zone matching—a common trap is assuming a source address object alone guarantees policy match, ignoring the zone-to-VR binding. Remember the memory tip: “Zone is local, VR is global; a wrong VR means a wrong zone.”

PCNSA Policy Evaluation and Management Practice Question

This PCNSA practice question tests your understanding of policy evaluation and management. 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 Networks firewall with multiple virtual routers. The security policy has a rule that allows SSH from the 'Internal' zone to the 'DMZ' zone. Recently, a new subnet 10.10.20.0/24 was added to the Internal zone. Users in that subnet report they cannot SSH to a server at 192.168.1.10 in the DMZ, while users from other subnets in Internal can. The rule has source address object '10.0.0.0/8' which includes the new subnet. The rule's source zone is Internal, destination zone is DMZ, and application is SSH. The administrator confirms the new subnet's IPs are within 10.0.0.0/8. What is the most likely cause of the problem?

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.

Question 1hardmultiple choice

Read the full NAT/PAT explanation →

A
The application is not correctly identified because the SSH server uses a non-standard port.
Why wrong: Incorrect. The problem is zone/VR-related, not application identification.
B
There is a deny rule placed above the allow rule that matches the new subnet but not the other subnets.
Why wrong: Incorrect. While possible, the question states other subnets in Internal work, so a deny rule specific to the new subnet is unlikely.
C
The firewall's route table has a more specific route for 10.10.20.0/24 pointing to a different virtual router, causing traffic from that subnet to enter via an interface in a different zone.
Correct. If the subnet's traffic enters via a different VR and zone, the security policy rule (which expects the Internal zone) will not match.
D
The rule's source address object is incorrectly defined as '10.0.0.0/8' but the new subnet is not actually within that range.
Why wrong: Incorrect. The subnet 10.10.20.0/24 is within 10.0.0.0/8, so the object includes it.

Full breakdown with real-world context →

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 firewall's route table has a more specific route for 10.10.20.0/24 pointing to a different virtual router, causing traffic from that subnet to enter via an interface in a different zone.

The most likely cause is that the new subnet is routed through a different virtual router (VR) than the one used by the Internal zone's interface. The security policy is zone-based, but if the traffic ingresses via an interface in a different VR, the zone association may change, preventing the rule from matching. Option A correctly identifies this scenario.

Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

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 application is not correctly identified because the SSH server uses a non-standard port.
Why it's wrong here
Incorrect. The problem is zone/VR-related, not application identification.
✗
There is a deny rule placed above the allow rule that matches the new subnet but not the other subnets.
Why it's wrong here
Incorrect. While possible, the question states other subnets in Internal work, so a deny rule specific to the new subnet is unlikely.
✓
The firewall's route table has a more specific route for 10.10.20.0/24 pointing to a different virtual router, causing traffic from that subnet to enter via an interface in a different zone.
Why this is correct
Correct. If the subnet's traffic enters via a different VR and zone, the security policy rule (which expects the Internal zone) will not match.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
CIDR notation defines the prefix length.
✗
The rule's source address object is incorrectly defined as '10.0.0.0/8' but the new subnet is not actually within that range.
Why it's wrong here
Incorrect. The subnet 10.10.20.0/24 is within 10.0.0.0/8, so the object includes it.

Common exam traps

Common exam trap: usable hosts are not the same as total addresses

Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.

Detailed technical explanation

How to think about this question

Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.

KKey Concepts to Remember

CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.

TExam Day Tips

Write the block size before choosing the subnet.
Check whether the question asks for hosts, subnets or a specific address range.
Do not confuse /24, /25, /26 and /27 host counts.

Key takeaway

Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.

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.

Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related PCNSA subnetting questions on CIDR, address ranges, and subnet selection.

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.

10 questions 20 questions 30 questions 50 questions Timed 30

PCNSA practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this PCNSA question test?

Policy Evaluation and Management — This question tests Policy Evaluation and Management — CIDR notation defines the prefix length..

What is the correct answer to this question?

The correct answer is: The firewall's route table has a more specific route for 10.10.20.0/24 pointing to a different virtual router, causing traffic from that subnet to enter via an interface in a different zone. — The most likely cause is that the new subnet is routed through a different virtual router (VR) than the one used by the Internal zone's interface. The security policy is zone-based, but if the traffic ingresses via an interface in a different VR, the zone association may change, preventing the rule from matching. Option A correctly identifies this scenario.

What should I do if I get this PCNSA question wrong?

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?

CIDR notation defines the prefix length.

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 →

How Courseiva writes practice questions · Editorial policy

Last reviewed: Jun 24, 2026

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.

Loading comments…

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.