PCNSA Securing Traffic Practice Question
A security administrator has configured a security policy rule to allow SSH from the Trust zone to the Untrust zone. The rule uses the application 'ssh' and the service 'application-default'. Users report that SSH connections to external servers on port 2222 are failing, while SSH on port 22 works. What is the most likely cause of the failure?
⚠ Common exam trap
The trap here is assuming that selecting the 'ssh' application automatically allows SSH on any port, when the service setting controls the port.
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 service 'application-default' only allows the default port for the application, so port 2222 is blocked.
The service 'application-default' restricts traffic to the default ports of the selected applications. For SSH, the default port is 22, so connections on port 2222 are blocked. To allow SSH on a non-standard port, the administrator must either set the service to 'any' or create a custom service for port 2222 and apply it to the rule. This ensures that the firewall permits the traffic on the desired port while still identifying it as SSH.
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 'ssh' does not support non-standard ports; a custom application must be created.
Why it's wrong here
The ssh application in Palo Alto Networks can detect SSH on non-standard ports through App-ID, but the service 'application-default' restricts the port to the default (22). If the service is set to application-default, traffic on port 2222 will not match because it is not the default port. The application itself can identify SSH on other ports if the service is set to 'any' or a custom service. Therefore, this option is incorrect because the ssh application does support non-standard ports when the service allows it.
- ✗
The application 'ssh' is not included in the rule's application list; instead, 'any' is used.
Why it's wrong here
The scenario states the rule uses the application 'ssh', so this option contradicts the given information. If the application were 'any', SSH on port 2222 might be allowed if the service is 'any', but that is not the case. Therefore, this option is incorrect because it does not reflect the actual configuration.
- ✗
The security policy rule is missing a URL filtering profile to allow SSH on port 2222.
Why it's wrong here
URL filtering profiles are used for web traffic and do not affect SSH. SSH is not a web-based application, so URL filtering is irrelevant. The failure is due to the service restriction, not URL filtering. This option is incorrect because it applies a web-specific control to a non-web protocol.
- ✓
The service 'application-default' only allows the default port for the application, so port 2222 is blocked.
Why this is correct
The service 'application-default' enforces the default port for the selected application. For ssh, the default port is 22. Therefore, traffic on port 2222 is not allowed because it does not match the default port. To allow SSH on port 2222, the administrator must either change the service to 'any' or create a custom service for port 2222 and attach it to the rule. This option correctly identifies the cause of the failure.
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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.