TroubleshootingOverview 9-11
9
9.5 Specific Problems and Solutions

9.5.1 Failure of Network Communications

Descriptionof the Problem

The system cannot communicate with a network if the system and the network
hub are not set in the same way for the Ethernet Link Integrity Test.This
problem particularly applies to 10BASE-T network hubs, where the Ethernet
Link Integrity Testis optional. This is not a problem for 100BASE-T networks,
where the test is enabled by default.
If you connect the system to a network and the network does not respond, use
the OpenBoot command watch-net-all to display conditions for all network
connections:
For SBus Ethernet cards, the test can be enabled or disabled with a hardware
jumper,which you must set manually. For the TPE and MII onboard ports on
the I/O board, the link test is enabled or disabled through software,as shown
below.
Remember also that the TPE and MII ports are not independent circuitsand as
a result, both ports cannot be used at the same time.
Note – Some hub designs do not use a software command to enable/disable
the test, but instead permanently enable (or disable) the test through a
hardware jumper.Refer to the hub installation or user manual for details of
how the test is implemented.

Determiningthe Device Names of the I/O Boards

Toenable or disable the link test for an on-board TPE (hme) port, you must first
know the device name for the I/O board. Tolist the device names:
1. Shut down the system and take the system into OpenBoot.
2. Determine the device names of the I/O boards:
ok watch-net-all