PCNSE Practice Question: Securing Users and Applications with Authentication
A security administrator notices that users are able to bypass authentication by accessing resources using IP addresses instead of FQDNs, even though authentication policies are configured. How can this be prevented?
⚠ Common exam trap
Watch out — candidates often assume enabling User-ID on the interface or using decryption will solve the bypass, but they miss the critical detail that authentication policies must explicitly target unmapped IPs via the 'unknown' source user to enforce authentication for IP-based access.
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
✓
Configure an authentication policy with source user 'unknown' to enforce authentication for all unmapped IP addresses.
When users access resources by IP address rather than FQDN, the firewall cannot associate the traffic with a specific user via normal authentication policies (which rely on domain-based rules). By configuring an authentication policy with source user 'unknown', the firewall forces authentication for all unmapped IP addresses, ensuring that even IP-based access triggers user identification and policy enforcement.
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 policy to decrypt all traffic.
Why it's wrong here
Decryption does not interact with authentication enforcement.
- ✗
Use identity-based routing to enforce authentication.
Why it's wrong here
Identity-based routing is for policy-based routing, not authentication.
- ✗
Enable user-ID on the ingress interface and configure authentication policy for IP addresses.
Why it's wrong here
This is already assumed; the issue is that the existing authentication policy may not match the IP address range. More specific is needed.
- ✓
Configure an authentication policy with source user 'unknown' to enforce authentication for all unmapped IP addresses.
Why this is correct
By default, authentication policies match on source user 'any', so if a user mapping exists, the policy applies. Setting source user to 'unknown' ensures that traffic from IPs without a user mapping triggers authentication.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCNSE 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 PCNSE exam.