Adding a second FMC to a production deployment

[packet2020]

Hi All,

I currently have a single FMC and ~ 20 FTDs in a production deployment. I'm preparing to add a second FMC in HA and wanted to check if this would result in any downtime or impact to the live FTDs during FMC HA establishment. From what I understand, when adding the second FMC into HA, a script is run on all FTDs in the deployment to instruct them to register with the second FMC node, however its not clear if this will be distruptive and if its advised to perform the FMC HA configuration during a maintenance window, or if the process is completley non-distruptive. Thanks

[Kasun Bandara]

@packet2020 hi, its a good practice to take a maintenance window for this kind of activities. According to guide, critical background services may interrupt. 

https://www.cisco.com/c/en/us/support/docs/security/secure-firewall-management-center/221089-configure-high-availability-on-fmc.html