3Com 3CR17661-91, 3CR17662-91, 3CR17660-91 manual Solving Hardware, Problems

Solving Hardware Problems 55

Auto-negotiation problems will occur with 10BASE-T or 100BASE-T where auto-negotiation is disabled and incorrect cables are being used (cross-over or straight)

Auto-negotiation problems will occur with fiber if:

■The Receiver (RX) and Transceiver (TX) cable connectors are swapped

■Fibers are broken

■Auto-negotiation differs at either end (a link appears at the ‘fixed’ end and not at the auto-negotiation end)

Solving Hardware	In the rare event of your Switch unit experiencing a hardware failure,
Problems	refer to the list of suggested solutions below.

A fan failure warning message is received

Your Switch has a fan monitoring system that will generate fan failure warning messages. Fan failure could potentially reduce the lifetime of the Switch. The monitoring system polls the fan status at periodic intervals while the unit is powered up.

If one fan has failed in the Switch, a warning message will be generated in the following ways:

■Unit LED

The seven segment display will show a green flashing ‘f’.

■RMON Trap

If configured, an RMON trap is generated and sent to the management workstation.

■Command Line Interface

An indication of a general hardware failure is provided through the Top level menu displayed when logging on to the CLI. For more detailed information about the failure select the display logbuffer command.

■Web interface

An indication of fan failure is provided through the Device Summary table for the specific unit. In addition all Summary tables turn red to indicate the fan failure.