Chapter 3 Troubleshooting; Understanding Post Results - Cisco Catalyst 3750 Hardware Installation Manual

Troubleshooting
The LEDs on the front panel provide troubleshooting information about the switch. They show failures
in the power-on self-test (POST), 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 command-line interface (CLI), or from
a Simple Network Management Protocol (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.
This chapter describes these topics for troubleshooting problems:
•
•

Understanding POST Results

As the switch powers on, it begins the power-on self-test (POST), a series of tests that runs automatically
to ensure that the switch functions properly. POST lasts approximately 1 minute.
When the switch begins POST, the System, the RPS, the Master, the Status, the Duplex, the Speed, and
the Stack LEDs turn green. (On the Power over Ethernet [PoE] Catalyst 3750 switches, the PoE LED
also turns green as POST begins.) The System LED flashes green, and the other LEDs remain continuous
green.
When POST completes successfully, the System LED remains green. The RPS LED remains green for
some time and then returns to its operating status. The other LEDs turn off and return to their operating
status.
Note For information on operating status for the LEDs, go to the
POST failures are usually fatal. Call Cisco Systems if your switch does not pass POST.
Note
OL-6336-06
Understanding POST Results, page 3-1
Replacing a Failed Stack Member, page 3-7
C H A P T E R
"LEDs" section on page 1-14.
"LEDs" section on page
Catalyst 3750 Switch Hardware Installation Guide
3
1-14.
3-1