PCNSA Securing Traffic Practice Question
A company has a firewall configured with multiple virtual routers. A user on a trusted network can ping the firewall's management IP but cannot reach an external server. The security policy allows the traffic. What is the most likely cause?
⚠ Common exam trap
Watch out — candidates often confuse routing issues with security policy or NAT problems, but the firewall must have a viable route in the virtual router before it can forward any traffic, regardless of policy allowances.
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 virtual router does not have a default route to the external network.
The most likely cause is that the virtual router lacks a default route to the external network. Even though the security policy permits the traffic, the firewall must have a route in the virtual router's routing table to forward packets toward the destination. Without a default route, the firewall drops the traffic because it cannot determine the next hop for the external server's IP address.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
A zone protection profile is blocking ICMP packets.
Why it's wrong here
Zone protection profiles apply to ingress traffic on a zone and can drop ICMP, but the user successfully pings the firewall's management IP, proving ICMP reaches the device. It tempts because zone protection does block flood and reconnaissance traffic. The likely cause is virtual-router or inter-zone forwarding configuration.
- ✓
The virtual router does not have a default route to the external network.
Why this is correct
The management interface responds because it sits on the firewall itself, but forwarding to an external server requires the virtual router to hold a default route toward the untrusted next hop. Without it, the permitted traffic is dropped for lack of a route.
- ✗
The decryption policy is blocking the traffic because it is not decrypted.
Why it's wrong here
Decryption policy only inspects traffic matching its rules; unencrypted ping/HTTP traffic is bypassed, not blocked, so it cannot explain the failure. It is tempting because decryption failures do cause silent drops, but that applies when sessions are actually encrypted and a decryption profile rejects them.
- ✗
The NAT policy is missing for the outbound traffic.
Why it's wrong here
NAT is applied after the security policy and is required for outbound translation, but the stem states the security policy allows the traffic and the user reaches the firewall's management IP, so the failure lies in virtual-router routing or inter-zone forwarding. NAT policy is the correct focus when translation itself is absent.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.