Specific Problems And Solutions; Failure Of Network Communications - Sun Microsystems Enterprise 6500 Reference Manual

Refer to the Solstice SyMON User's Guide, part number 802-5355, for starting and
operating instructions.
9.4

Specific Problems and Solutions

9.4.1

Failure of Network Communications

Description of 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
Test is 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:
ok watch-net-all
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.
Note – The TPE and MII ports share some circuitry so do not try to use the two
ports 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.
Chapter 9 Troubleshooting Overview 9-11