PCNSA Policy Evaluation and Management Practice Question
A network security administrator needs to create a rule that allows DNS traffic from the Trust zone to the Untrust zone. Which application should be selected in the security rule to allow DNS?
⚠ Common exam trap
A common mix-up: candidates confuse the DNS application with other common applications like web-browsing or ssl, which do not cover DNS traffic.
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
✓
dns
The correct application to allow DNS traffic is 'dns'. This application is predefined in PAN-OS and matches DNS queries and responses on port 53. Selecting it in a security rule ensures that DNS traffic from Trust to Untrust is permitted, allowing clients to resolve domain names.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
ssl
Why it's wrong here
The 'ssl' application identifies SSL and TLS encrypted traffic, commonly used for HTTPS. It does not cover DNS, which is typically unencrypted and uses UDP/TCP port 53. If 'ssl' is selected, DNS traffic would not match the rule and would be blocked by the default deny rule, causing resolution failures for clients in the Trust zone.
- ✗
ping
Why it's wrong here
The 'ping' application identifies ICMP echo requests and replies. It is used for connectivity testing, not for DNS. Allowing 'ping' would not permit DNS queries. To allow DNS, the 'dns' application must be selected. Using 'ping' would result in DNS traffic being blocked, disrupting name resolution for users.
- ✓
dns
Why this is correct
The 'dns' application in PAN-OS is specifically designed to identify and allow DNS traffic. When selected in a security rule, it permits DNS queries and responses over UDP and TCP port 53. This is the correct application to use for allowing DNS traffic from the Trust zone to the Untrust zone, ensuring that name resolution functions properly.
- ✗
web-browsing
Why it's wrong here
The 'web-browsing' application identifies HTTP and HTTPS traffic used for web browsing, not DNS. Allowing web-browsing would not permit DNS queries, as DNS uses different protocols and ports. This application is inappropriate for the scenario, and selecting it would leave DNS traffic blocked, preventing name resolution for users in the Trust zone.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Palo Alto Networks exam blueprint
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.