The host subsystem consists of a routing engine installed in a switch control board (SCB). The host subsystem provides the routing and system management functions of the services gateway. You must install one host subsystem on the device. Each host subsystem functions as a unit; the Routing Engine must be installed directly into the Switch Control Board. For more information about the host subsystem components, see Switch Control Board and Routing Engine.
The host subsystem has three LEDs that display its status. The host subsystem LEDs are located on the upper left of the craft interface. For more information about the host subsystem LEDs, see Host Subsystem LEDs.