What happens when a routed VLAN interface (RVI) is configured on a FortiSwitch port or...

According to theFortiSwitchOS 7.6 Administration Guideand theFortiSwitch 7.6.1 Administration Guide—Standalone Mode, aRouted VLAN Interface (RVI)is a physical port or trunk interface that is converted to support Layer 3 routing protocols.2This transformation changes the fundamental nature of the interface from a switching component to a routing component.

When an RVI is enabled on a specific physical port or trunk, the system automatically assignsVLAN 4095to that interface at the backend.3This specific VLAN ID is reserved across the FortiSwitch platform to signal that the interface is no longer operating as a standard Layer 2 switch port.4Once configured as an RVI, the interface supports advanced Layer 3 features such asOSPF, BGP, RIP, IS-IS, and static routing, as well asVirtual Routing and Forwarding (VRF)for routing isolation.5

Importantly, the documentation states that upon enabling RVI,Layer 2 protocols(such as Spanning Tree Protocol or 802.1X port-based security) and most standard switch interface features aredisabledon that port.6This is because the port is now treated as a dedicated Layer 3 " routed " interface rather than a member of the Layer 2 switching fabric.7Additionally, if the underlying physical port or trunk interface is administratively shut down, the associated RVI will also transition to a " down " state.