What steps need to be followed if one of the HA device is out of order ?

Hello Sarovani,

There are two scenarios,

First one is that you don't  have a backup UCS from the defective device and don't have the master key of it and in this scenario you have to do the below:

- power on the new RMA device, License it and configure initial configuration like MGMT IP, VLANs , Self IPs , NTP , DNS and HA configurations like the defective device was configured to make it as an HA peer to the active device.

- Then you can sync the configurations from the active device.

Second one is that you have a backup UCS from the defective device and also the master key and in this scenario you have to do the below:

- power on the new RMA device, License it and rekey RMA unit with the master ke and then restore UCS backup using no-license option.

- then sync the configurations.

_ for test, failover between the active device and RMA Device to be sure that traffic is working on the new RMA device.

_ in all scenarios, make sure that the new device is to be offline till you will be ready to make it as online to test traffic on.

+ to get Master key >>>>> use this command : f5mku -K

+ to rekey the new device >>> f5mku -r <key_value>

this is described in this link : https://support.f5.com/csp/article/K9420

I hope it is clear for you.