Cisco 2431 - IAD Router Hardware Installation Manual page 55

Chapter 3 Troubleshooting
Table 3-1
Symptom
No connectivity
Unreadable characters on the
management console
Amber system LED
The switch port is placed in
error-disabled state after SFP
module is inserted
OL-7678-01
Common Problems and Their Solutions (continued)
Possible Cause
Incorrect or bad cable
These are results of no link at both
ends:
A crossover cable was used
•
when a straight-through was
required, or the reverse.
The cable is wired incorrectly.
•
A crossover or straight-through
•
cable is wired incorrectly.
STP checking for possible
•
loops. STP is available only on
network node interfaces (NNIs).
Incorrect baud rate.
Fatal POST error detected.
Bad or non-Cisco-approved SFP
module.
Cisco ME 2400 Ethernet Access Switch Hardware Installation Guide
Diagnosing Problems
Resolution
For the correct pinouts and
•
the proper application of
crossover instead of
straight-through cables, see
the "Two Twisted-Pair
Cable Pinouts" section on
page B-3.
Enable the automatic
•
medium-dependent-
interface crossover
(auto-MDIX) feature.
Replace with a tested good
•
cable.
• For 1000BASE-T
connections, be sure to use
a twisted four-pair,
Category 5 cable.
Wait 30 seconds for the port
•
LED to turn green.
Reset the emulation software to
9600 baud.
Contact Cisco Systems.
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-disabled state.
See the switch command
reference guide for information
on the errdisable recovery
command.
3-3