PCNSE Practice Question: Managing Troubleshooting and High Availability
After a power failure, both firewalls in an HA pair come up and report 'active' state. The network team confirms that the two firewalls are connected via HA1 and HA2. What is the most likely cause of the split-brain condition?
⚠ Common exam trap
It's easy for candidates to confuse the HA1 keepalive timer with the HA2 link's role in election, assuming HA2 is involved in determining active/passive state, when in fact HA2 is only for session synchronization and not for election.
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 HA1 keepalive hold timer is set too low, causing both to become active before learning peer state
The HA1 keepalive hold timer determines how long a firewall waits for a hello message from its peer before declaring it dead. If this timer is set too low, both firewalls may boot up and not receive each other's initial keepalives in time, causing each to assume the other is unavailable and transition to active state. This results in a split-brain condition where both firewalls operate independently.
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 HA1 keepalive hold timer is set too low, causing both to become active before learning peer state
Why this is correct
A short hold timer can lead to premature failover during boot.
- ✗
The active firewall has a higher software version
Why it's wrong here
Version mismatch would be detected.
- ✗
Preemption is enabled on both firewalls
Why it's wrong here
Preemption would cause one to become active after the other is already active.
- ✗
HA2 link is configured but not used for election
Why it's wrong here
HA2 does not affect election.
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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.