Cisco ME-C3750-24TE-M Hardware Installation Manual page 116

Diagnosing Problems
Table 4-1 Common Problems and Solutions (continued)
Symptom
The switch port is placed in
error-disabled state after SFP is
inserted
Switch does not recognize the
SFP module
No stack link between switches
or high error rate between
switches in the stack
Catalyst 3750 Switch Hardware Installation Guide
4-6
Possible Cause
Bad or non-Cisco-approved SFP.
The SFP module might be installed
upside down.
The SFP module does not snap into
the slot.
Poor cable connection.
Bad StackWise cable or damaged
StackWise port.
Chapter 4 Troubleshooting
Resolution
Remove the SFP module from
the switch, and replace it with a
Cisco-approved module. Use the
errdisable recovery cause
gbic-invalid global
configuration command to
verify the port status, and enter a
time interval to recover from the
error-disable state.
Refer to the switch command
reference guide for information
on the errdisable recovery
command.
Verify that the SFP module is
not installed upside down.
Remove the SFP module.
Inspect for physical damage to
the connector, the module, and
the module slot.
Replace the SFP module with a
known good SFP module.
Secure the thumb screws on the
StackWise cables. See
Figure 3-35.
Remove the StackWise cable,
and inspect the cable and
StackWise port for bent pins or
damaged connectors.
If the StackWise cable is bad,
replace it with a known good
cable.
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