FMC High Availability. High Availability is available on physical Firepower Management Center appliances (and FMCv since 6.7. 0). Before configuring FMC HA make sure that: * Hardware is identical (no mix and match between virtual and/or physical form factors) * Software release is identical on both FMCs * There are no sensors registered to the secondary FMC https://www.cisco.com/c/en/us/td/docs/security/firepower/620/configuration/guide/fpmc-config- guide-v62/firepower_management_center_high_availability.html