You must add devices to the FortiManager system to use FortiManager to manage the devices. You must also enable Central Management on the managed device by using FortiOS. You can add an existing, operational device or an unregistered device. You can also provision a new device.
You can add individual devices or multiple devices. Adding devices using the Add Device wizard gives you more configuration options than using Add Multiple devices.
For a device that is currently online, use the Add Device wizard, select Discover, and follow the steps in the wizard. Adding an existing device does not result in an immediate connection to the device. Device connection happens only when you successfully synchronize the device. To provision a new device which is not yet online, use the Add Device wizard and select Add Model Device.
Adding an operating FortiGate HA cluster to the Device Manager pane is similar to adding a standalone device. Specify the IP address of the master device. FortiManager handles a cluster as a single managed device.
If you are using a HA cluster, you can promote a slave device to a master device. Go to Device Manager > Device & Groups > Managed FortiGate > [HA_Cluster_Name]. The System:Dashboard pane shows the cluster members under Cluster Members. Click Promote to promote a slave device to a master device.