Cisco Catalyst 3750 - Diagnosing Problems

4-5
Catalyst 3750 Switch Hardware Installation Guide
78-15136-03
Chapter 4 Troubleshooting
Diagnosing Problems
Table 4-1 Common Problems and Solutions
Symptom Possible Cause Resolution
Poor performance or excessive
errors
Duplex autonegotiation mismatch. Refer to the switch software
configuration guide for
information on identifying
autonegotiation mismatches.
Verify that the autonegotiation
settings are the same at both
ends.
Cabling distance exceeded
•
Port statistics show excessive
frame check sequence (FCS),
late-collision, or alignment
errors.
• For 10/100 and
10/100/1000BASE-T
connections:
– The distance between the
port and the attached device
exceeds 328 feet (100
meters).
– If the switch is attached to a
repeater, the total distance
between the two end
stations exceeds the cabling
guidelines.
• SFP or XENPAK cabling
guidelines exceeded.
• Refer to the switch software
configuration guide for
information on displaying
port statistics.
• Reduce the cable length to
within the recommended
distances.
• Refer to your repeater
documentation for cabling
guidelines.
• Refer to your SFP or
XENPAK documentation
for cabling guidelines.
Bad adapter in attached device
•
Excessive errors found in port
statistics.
• STP checking for possible
loops.
• Run adapter card diagnostic
utility.
• Wait 30 seconds for the port
LED to turn green.