Why Does the Active Firewall Require a Longer Preemption Delay Than That on the Standby Firewall?
Preemption starts after the original active firewall recovers. If the preemption delay of the active firewall is too shorter than that on the standby firewall, the active firewall may switch status before the session entries on the standby firewall are completely synchronized to the active firewall. As a result, some services may be interrupted. Therefore, the active firewall requires a longer preemption delay.
Preemption does not start after the standby firewall recovers. Therefore, preemption delay is meaningless for the standby firewall and you can use the default preemption delay.