IBM 21Y Maintenance Manual page 28

Table 1. Ethernet troubleshooting chart
Ethernet
controller
problem
Ethernet Link
Status light
does not
light.
The Ethernet
Transmit/
Receive
Activity light
does not
light.
Data is
incorrect or
sporadic.
Suggested Action
Check the following:
• Make sure that the hub is turned on.
• Check all connections at the Ethernet
controller and the hub.
• Check the cable. A crossover cable
is required unless the hub has an X
designation.
• Use another port on the hub.
• If the hub does not support auto-
negotiation, manually configure the
Ethernet controller to match the hub.
• If you manually configured the duplex
mode, make sure that you also
manually configure the speed.
• Run diagnostics on the LEDs.
Check the following:
Note: The Ethernet Transmit/Receive
Activity LED illuminates only when
data is sent to or by this Ethernet
controller.
• Make sure that you have loaded the
network device drivers.
• The network might be idle. Try
sending data from this workstation.
• Run diagnostics on the LEDs.
• The function of this LED can be
changed by device driver load
parameters. If necessary, remove
any LED parameter settings when
you load the device drivers.
Check the following:
• Make sure that you are using
Category 5 cabling when operating
the server at 100 Mbps.
• Make sure that the cables do not run
close to noise-inducing sources like
fluorescent lights.
Diagnostics
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