Technical Tip: Steps to rebuild a cluster

1. Back up the configuration from the current Primary node.
   
   
2. Access the FortiWeb unit that needs to be added to the cluster, and run the command 'get system status' to verify if the firmware version is the same as that of the Primary (currently in production).
   
   
3. Ensure that the firmware version on the unit to be added is the same as that of the Primary.
   
   
4. If the firmware version is different from the current unit in production, access the appliance through management IP and upgrade the firmware via GUI or upgrade firmware via TFTP.

For instructions on firmware installation via CLI, refer section 'To install firmware via the CLI' from the following link: 

Updating the firmware - FortiWeb administration guide.

5. From the Primary unit config copy the HA settings. Some of the most critical parameters are:

Mode
Device priority
group-name
group-id
monitored interfaces ("monitor")
hbdev (heartbeat interface/device)

6. Connect only the heartbeat interfaces and wait for the HA formation and synchronization to be successful. Verify this by executing the following commands on the Primary:

    

get sys ha-status <- To verify if the newly added node is seen in the cluster.
execute ha md5sum <- To verify the checksum from master and slave matches.

7. Once HA formation and synchronization are successful, connect the remaining interfaces.