Download Guidelines for High Availability FMCs
When upgrading Firepower Management Centers in a high availability configuration, you must transfer packages to both the active/primary FMC and the standby/secondary FMC. Additionally, you must pause synchronization before you transfer the package to the standby FMC.
To limit interruptions to high availability synchronization during the upgrade process, we recommend that you:
Active FMC—Transfer the package during the preparation stage of the upgrade.
Standby FMC—Transfer the package as part of the actual upgrade process, after you pause synchronization.
For more information, see Upgrade High Availability FMCs.