status LEDs, such as Enabled and Active LEDs, are usually on the front of the chassis. The
interface specific LEDs are on the back of the chassis, adjacent to the interface in question.
the model by model differences in mind for individual routers, this discussion focuses on only
a couple chassis models, rather than all the models that have been discussed in this chapter.
architecture in that the CON and AUX ports are on the front of the box. This has received mixed
reviews overall. The LEDs that share the front of the box with the CON and AUX ports enable
the administrator to monitor at a glance the status of the router. The Ready LED (located on the
front of the router) indicates that a functional network module is in the indicated slot. As traffic
traverses the router, the Activity LED blinks according to the volume of the traffic. The Enable
LED specifies whether the module has passed the power on self-test (POST). Obviously, if no
module has been inserted into a particular slot, the appropriate LEDs remain dark. Figure 3-4
illustrates the positioning of the LEDs on the 3640 router.