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.
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.
The TPE and MII ports share some circuitry so do not try to use the two ports at the same time.
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.