Troubleshooting

Separate procedures are provided for troubleshooting Fast Ethernet and FDDI modules.

100BaseT Modules

When first powered on, the expansion slot LED of the Catalyst 2820 and all LEDs on the module front panel are green. A power-on self-test (POST) is automatically started. If the module passes the POST, the expansion slot LED on the Catalyst 2820 remains green. If the module fails the POST, the expansion slot LED turns amber.

If the LEDs do not come on at all, use Table 4-1 to determine the appropriate action to take.

Table  4-1: Troubleshooting Fast Ethernet Modules

Symptom	Possible Cause	Corrective Action
Link LED is off	No cable connected	Connect both ends of a cable to a device.
	Device has no power	Ensure that both devices have power.
	Module not enabled	Check management console to ensure that the module is enabled.
	Wrong cable type	Verify the cable selection (crossover versus non-crossover).
	Bad cable	Replace with known good cable.
Expansion slot LED is off	Module not installed properly	Remove module and reinstall.

FDDI Modules

When first powered on, the expansion slot LED of the Catalyst 2820 and all LEDs on the module front panel are green. A power-on self-test (POST) is automatically started. If the module passes the POST, the expansion slot LED on the Catalyst 2820 remains green. If the module fails the POST, the expansion slot LED turns amber. The "POST for FDDI" section in the "Installation" chapter describes how to use the module LEDs to interpret the nature of POST failures for FDDI modules.

If the LEDs do not come on at all, use Table 4-2 to determine the appropriate action to take.

Table  4-2: Troubleshooting FDDI Modules

Symptom	Possible Cause	Corrective Action
Connected LED is off	No cable connected	Connect both ends of a cable to a device.
	Module not enabled	Check management console to ensure that the module is enabled.
	Wrong UTP cable type	If UTP, verify that the cable selection is a CDDI cable.
	Bad cable	Replace cable with a known good cable.
Expansion slot LED is off	Module not installed properly	Remove module and reinstall.
	Device not powered on	Ensure that Catalyst 2820 has power.