Hardware requirements

Hardware requirements are specifications that ensure two units in a High availability configuration can

  • maintain identical hardware configurations including model, interfaces, modules, and RAM

  • support proper synchronization and failover functionality, and

  • ensure reliable high availability operation.

Hardware requirement specifications

The two units in a High availability configuration must meet these requirements:

  • Be the same model.

    For the Firepower 9300, High Availability is only supported between same-type modules. However, 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.

  • 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 these 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.