PCNSE Manage, Monitor and Operate Practice Question
Which THREE are common causes of high CPU utilization on a Palo Alto Networks firewall? (Choose three.)
⚠ Common exam trap
A common mix-up: candidates confuse disk space issues (Option C) with CPU utilization, but disk space problems affect storage and logging, not CPU directly, while BGP flapping (Option E) is a control-plane issue that is less commonly cited as a top cause of high CPU in Palo Alto Networks documentation.
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
✓
Large number of dynamic IP address group lookups.
A large number of dynamic IP address group lookups can cause high CPU utilization because each lookup requires the firewall to evaluate the dynamic group membership in real time, often involving LDAP or other directory queries. This process is computationally expensive, especially when policies trigger frequent lookups for every new session, leading to sustained CPU spikes.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Large number of dynamic IP address group lookups.
Why this is correct
Dynamic group lookups can be CPU intensive.
- ✓
Inefficient security policy rules causing excessive session processing.
Why this is correct
Poorly ordered rules with many matches can cause high CPU.
- ✗
Insufficient disk space on the log partition.
Why it's wrong here
Disk space affects storage, not CPU directly.
- ✓
Excessive logging due to very frequent session matches.
Why this is correct
High logging rate can consume CPU.
- ✗
BGP prefix flapping causing route recalculations.
Why it's wrong here
BGP flapping can cause CPU, but it's less common than the others; may be considered plausible but not a top three.
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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.