Single FortiGate unit managing a stack of several FortiSwitch units

The FortiGate unit connects directly to one FortiSwitch unit using a physical or aggregate interface. The remaining FortiSwitch units connect in a ring using inter-switch links (that is, ISL).

Optionally, you can connect a standby FortiLink connection to the last FortiSwitch unit. For this configuration, you create a FortiLink Split-Interface (an aggregate interface that contains one active link and one standby link).

NOTE:

• When you are using the aggregate interface on the FortiGate unit for the FortiLink interface, the lacp-mode of the FortiLink aggregate interface must be set to static. Unless MCLAG is enabled and you are using 6.2.0 or later, see Transitioning from a FortiLink split interface to a FortiLink MCLAG for details.
• Do not create loops or rings with the FortiGate unit in the path.