Switch Startup

The startup process for a Cisco switch can be monitored in the following ways:

• Observing the light-emitting diodes (LEDs) on the switch chassis

• Examining the Cisco Internetwork Operating System (IOS) output by connecting a terminal to the switch's console port

Cisco catalyst switches have several LEDs that give a convenient visual indicator of the switch's operational status. These LEDs are green when the switch is functioning properly and amber when there's any sort of problem.

The Catalyst 1900 series switch executes a power-on-self-test (POST) each time the switch is powered on, which can be monitored by watching the LEDs on the switch chassis. The typical sequence is as follows :

1. Initially, all LEDs are green.

2. Each LED is associated with a specific POST. Each LED turns off after its task is complete or turns amber if there's a problem.

3. The system LED turns amber if any test fails.

4. When the POST is complete, the LEDs blink, then turn off.

In addition to monitoring LEDs, any errors encountered during startup can be checked by attaching a terminal to the console port of the switch and observing the text output. The initial output from a Catalyst 1900 switch with no errors looks similar to the following:

 Catalyst 1900 Management Console Copyright (c) Cisco Systems, Inc.1993-1999 All rights reserved. Standard Edition Software Ethernet address:   00-E0-1E-7E-B4-40 PCA Number: 73-2239-01 PCA Serial Number: SAD01200001 Model Number: WS-C1924-A System Serial Number: FAA01200001 --------------------------------- User Interface Menu [M] Menus [K] Command Line [I] IP Address [P] Console Password Enter Selection: