Chapter 6 Troubleshooting; Diagnosing Problems; Switch Post Results; Switch Leds - Cisco Catalyst 3850 Hardware Installation Manual

Troubleshooting
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Diagnosing Problems

The switch LEDs provide troubleshooting information about the switch. They show POST failures,
port-connectivity problems, and overall switch performance. You can also get statistics from the CLI,
or an SNMP workstation. See the software configuration guide, the switch command reference guide on
Cisco.com, or the documentation that came with your SNMP application for details.

Switch POST Results

Approximately 30 seconds after the switch powers on, it begins the power-on self-test (POST), which
can take up to 5 minutes to complete. During POST, the SYSTEM LED blinks green. When POST is
complete, the SYSTEM LED turns solid green, the ACTV LED is green if the switch is acting as the
active switch.
POST failures are usually fatal. Contact your Cisco technical support representative if your switch does
Note
not pass POST.

Switch LEDs

Look at the port LEDs for information when troubleshooting the switch. See the
page 1-9
OL-26779-02
Diagnosing Problems, page 6-1
Resetting the Switch, page 6-5
Finding the Switch Serial Number, page 6-6
Replacing a Failed Data Stack Member, page 6-6
for descriptions of the LED colors and their meanings.
C H A P T E R
Catalyst 3850 Switch Hardware Installation Guide
6
"LEDs" section on
6-1