Diagnosing Problems - Cisco Catalyst 3550 Hardware Installation Manual

Diagnosing Problems

The switch LEDs begin blinking after about 2 seconds.
Note
Continue holding down the Mode button. The LEDs stop blinking after 8 additional seconds, and then
Step 2
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
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
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:
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Catalyst 3550 Switch Hardware Installation Guide
3-2
If the switch is not configured, the LEDs are all green. You can omit Step 2 and run Express
Setup to configure the switch.
"LEDs" section on page
Field notices
Security advisories
Troubleshooting resources
Factory defaults
Password recovery
Recovery from corrupted or missing software
Switch port problems
Network interface cards
Troubleshooting tools
Appendix D, "Configuring the Switch with
1-6.
Chapter 3 Troubleshooting
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