– The cable must be securely attached at all connections. If the cable is attachedbut the problem remains, try a different cable.– If you set the Ethernet controller to operate at 100 Mbps, you must useCategory 5 cabling.– If you directly connect two servers (without a hub), or if you are not using ahub with X ports, use a crossover cable. To determine whether a hub has an Xport, check the port label. If the label contains an X, the hub has an X port.v Determine whether the hub supports auto-negotiation. If it does not, tryconfiguring the integrated Ethernet controller manually to match the speed andduplex mode of the hub.v Check the Ethernet controller LEDs on the rear panel of the server. These LEDsindicate whether there is a problem with the connector, cable, or hub.– The Ethernet link status LED is lit when the Ethernet controller receives a linkpulse from the hub. If the LED is off, there might be a defective connector orcable or a problem with the hub.– The Ethernet transmit/receive activity LED is lit when the Ethernet controllersends or receives data over the Ethernet network. If the Ethernettransmit/receive activity is off, make sure that the hub and network areoperating and that the correct device drivers are installed.v Check the LAN activity LED on the rear of the server. The LAN activity LED islit when data is active on the Ethernet network. If the LAN activity LED is off,make sure that the hub and network are operating and that the correct devicedrivers are installed.v Check for operating-system-specific causes of the problem.v Make sure that the device drivers on the client and server are using the sameprotocol.ResultsIf the Ethernet controller still cannot connect to the network but the hardwareappears to be working, the network administrator must investigate other possiblecauses of the error.Solving undetermined problemsIf Dynamic System Analysis (DSA) did not diagnose the failure or if the server isinoperative, use the information in this section.About this taskIf you suspect that a software problem is causing failures (continuous orintermittent), see “Software problems” on page 174.Corrupted data in CMOS memory or corrupted UEFI firmware can causeundetermined problems. To reset the CMOS data, use the CMOS clear jumper (JP1)to clear the CMOS memory and override the power-on password; see Table 2 onpage 30 for more information. If you suspect that the UEFI firmware is corrupted,see “Recovering the server firmware (UEFI update failure)” on page 179.If the power supplies are working correctly, complete the following steps:Chapter 4. Troubleshooting 177
