The devices in an HA pair can be assigned a
device
priority value to indicate a preference for which device
should assume the active role and manage traffic upon failover.
If you need to use a specific device in the HA pair for actively
securing traffic, you must enable the preemptive behavior on both
the firewalls and assign a device priority value for each device.
The device with the lower numerical value, and therefore
higher
priority, is designated as active and manages all traffic
on the network. The other device is in a passive state, and synchronizes
configuration and state information with the active device so that
it is ready to transition to an active state should a failure occur.