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Diagnosing problems – Cisco 3550 User Manual

Page 52

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3-2

Catalyst 3550 Switch Hardware Installation Guide

OL-6155-01

Chapter 3 Troubleshooting

Diagnosing Problems

The switch LEDs begin blinking after about 2 seconds.

Note

If the switch is not configured, the LEDs are all green. You can omit Step 2 and run Express
Setup to configure the switch.

Step 2

Continue holding down the Mode button. The LEDs stop blinking after 8 additional seconds, and then
the switch reboots.

The switch now behaves like an unconfigured switch. You can configure the switch by using Express
Setup as described in the getting started guide. You can also configure the switch by using the
command-line interface (CLI) setup procedure described in

Appendix D, “Configuring the Switch with

the CLI-Based Setup Program.”

Diagnosing Problems

The LEDs on the front panel provide troubleshooting information about the switch. They show POST
failures, port-connectivity problems, and overall switch performance. For a full description of the switch
LEDs, see the

“LEDs” section on page 1-6

.

You can also get statistics from the browser interface, from the CLI, or from an SNMP workstation.
See the software configuration guide and the switch command reference guide on Cisco.com or the
documentation that came with your SNMP application for details.

You can access the Cisco Technical Support website for a list of known hardware problems and extensive
troubleshooting documentation:

Field notices

Security advisories

Troubleshooting resources

Factory defaults

Password recovery

Recovery from corrupted or missing software

Switch port problems

Network interface cards

Troubleshooting tools