7.13About Diagnosing Specific Problems

7.13.1Network Communications Failure

7.13.1.1Symptom

The system is unable to communicate over the network.

7.13.1.2Action

Your system conforms to the Ethernet 10BASE-T/100BASE-TX standard, which states that the Ethernet 10BASE-T link integrity test function should always be enabled on both the host system and the Ethernet hub. The system cannot communicate with a network if this function is not set identically for both the system and the network hub (either enabled for both or disabled for both). This problem applies only to 10BASE-T network hubs, where the Ethernet link integrity test is optional. This is not a problem for 100BASE-TX networks, where the test is enabled by default. Refer to the documentation provided with your Ethernet hub for more information about the link integrity test function.

If you connect the system to a network and the network does not respond, use the OpenBoot PROM command watch-net-allto display conditions for all network connections:

ok watch-net-all

For most PCI Ethernet cards, the link integrity test function can be enabled or disabled with a hardware jumper on the PCI card, which you must set manually. (See the documentation supplied with the card.) For the standard TPE and MII main logic board ports, the link test is enabled or disabled through software.

Remember also that the TPE and MII ports share the same circuitry and as a result, you can use only one port at a time.

Note - Some hub designs permanently enable (or disable) the link integrity test through a hardware jumper. In this case, refer to the hub installation or user manual for details of how the test is implemented.

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Sun Microsystems 220R service manual About Diagnosing Specific Problems, Network Communications Failure, Symptom, Action