Troubleshooting

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

FDDI Modules

When FDDI modules are first installed, all of their LEDs light, and then the module runs a series of tests called the Power-On Self-Test (POST). If the module passes the POST, the module's enabled LED remains on. If the module fails the POST, the module's enabled LED blinks to indicate a problem. Table 4-1 lists some of the problems that can arise following the POST along with the actions you could take to correct them.

Table  4-1: Troubleshooting FDDI Modules

Symptom	Possible Cause	Corrective Action
Connected LED does not come on	No cable inserted	Insert both ends of the cable into a device.
	Module not enabled	Verify that the Module Enabled LED is lit.
	Wrong cable type	If UTP, verify that the cable selection is a cross-over FDDI cable.
	Bad cable	Replace cable with a known good cable.
Module Enabled LED does not come on	Module not installed properly	Remove module and reinstall.
	Device(s) not powered on	Ensure that FastSwitch has power.

Fast Ethernet Modules

When first powered on, all LEDs on the module front panel are on, and a Power-On Self-Test (POST) automatically begins. If the module passes POST, the Module Enabled LED on the FastSwitch remains on. If the module fails POST, the Module Enabled LED is off to indicate a problem.

Table 4-2 lists some symptoms of problems that may occur during POST and describes a possible cause and corrective action.

Table  4-2: Troubleshooting Fast Ethernet Modules

Symptom	Possible Cause	Corrective Action
Link LED does not come on	No cable inserted	Insert both ends of the cable into a device.
	Device has no power	Ensure that both devices have power.
	Module not enabled	Verify that the Module Enabled LED is on.
	Wrong cable type	Verify the cable selection (crossover versus non-crossover).
	Bad cable	Replace with known good cable.
Module Enabled LED does not come on	Module not seated properly	Remove module and reinstall.