Hardware Requirements

The two units in a High Availability configuration must:

  • Be the same model. In addition, for container instances, they must use the same resource profile attributes.

    For the Firepower 9300, High Availability is only supported between same-type modules; but the two chassis can include mixed modules. For example, each chassis has an SM-56, SM-48, and SM-40. You can create High Availability pairs between the SM-56 modules, between the SM-48 modules, and between the SM-40 modules.

    If you change the resource profile after you add the High Availability pair to the Security Cloud Control, update the inventory for each unit on the Devices > Device Management > Device > System > Inventory dialog box.

    If you assign a different profile to instances in an established high-availability pair, which requires the profile to be the same on both units, you must:

    1. Break high availability.

    2. Assign the new profile to both units.

    3. Re-establish high availability.

  • Have the same number and types of interfaces.

    For the Firepower 4100/9300 chassis, all interfaces must be preconfigured in FXOS identically before you enable High Availability. If you change the interfaces after you enable High Availability, make the interface changes in FXOS on the Standby unit, and then make the same changes on the Active unit.

  • Have the following settings in a remote branch deployment:

    • Have the same data management interface to handle management traffic in a remote deployment.

      For example, if you have used eth0 in device 1, use the same interface (eth0) in device 2 as well.

    • Use data management interface for management traffic.

      You cannot have one unit managed using a data interface and the other using a management interface.

If you are using units with different flash memory sizes in your High Availability configuration, make sure the unit with the smaller flash memory has enough space to accommodate the software image files and the configuration files. If it does not, configuration synchronization from the unit with the larger flash memory to the unit with the smaller flash memory will fail.