Cisco Systems 3550 manual Troubleshooting, Understanding POST Results, page, C H A P T E R

C H A P T E R 3

Troubleshooting

This chapter describes these troubleshooting topics:

•Understanding POST Results, page 3-1

•Clearing the Switch IP Address and Configuration, page 3-1

•Diagnosing Problems, page 3-2

Understanding POST Results

While the switch powers on, it automatically begins POST, a series of tests that verifies that the switch functions properly. POST lasts approximately 1 minute. When the switch begins POST, the port LEDs turn green, the system LED blinks green, the RPS LED turns off, and then the first two port LEDs turn off. When POST completes, the port LEDs return to the status mode display, and the system LED is green. If POST fails, the system LED is amber, and the port LED associated with the test is amber.

If POST fails, the SYST LED turns amber. Table 3-1 on page 3-3lists causes and resolutions for a POST failure. POST failures are usually fatal. Contact your Cisco representative if your switch does not pass POST.

Note The LEDs on a Catalyst 3550-24PWR switch function differently during POST. Use the console port to view the POST results.

Clearing the Switch IP Address and Configuration

If you have configured a new switch with a wrong IP address, or if all the switch LEDs start blinking when you are trying to enter Express Setup mode, you can clear the IP address that is configured on the switch.

Note This procedure clears the IP address and all configuration information stored on the switch. Do not follow this procedure unless you want to completely reconfigure the switch.

To clear the IP address and the switch configuration information, follow these steps:

Step 1 Press and hold the Mode button.

Catalyst 3550 Switch Hardware Installation Guide

OL-6155-01 3-1