In an active/passive HA setup, the recommended process for upgrading involves minimizing downtime and ensuring traffic continuity by using the failover process:
Suspend the active firewall: This triggers a failover to the passive unit, making it the active unit.
Upgrade the former passive (now active) unit: With traffic now running on the previously passive unit, upgrade the suspended unit while the active unit continues handling traffic.
Confirm proper operation: Once the upgrade is complete, verify that the upgraded unit is functioning properly.
Fail traffic back: Once the upgraded firewall is confirmed to be working, fail the traffic back to the original active unit and upgrade the remaining firewall.

Sandboxing executes suspicious files in an isolated environment and analyzes their behavior, making it effective against zero-day threats.

Deep packet inspection and threat analysis consume significant system resources.
Improper tuning or undersized hardware can lead to performance degradation.

Local firewall rules are evaluated after Panorama pre-rules (those applied before the firewall's local policies) and before Panorama post-rules (those applied after the firewall's local policies). This ensures that the local firewall rules do not override the central Panorama policy and are only applied in the appropriate order within the policy evaluation sequence.