Solving Ethernet controller problemsThe method that you use to test the Ethernet controller depends on which operatingsystem you are using. See the operating-system documentation for informationabout Ethernet controllers, and see the Ethernet controller device-driver readme file.Try the following procedures:v Make sure that the correct device drivers, which come with the server areinstalled and that they are at the latest level.v Make sure that the Ethernet cable is installed correctly.– The cable must be securely attached at all connections. If the cable isattached but 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 anX port, 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 is litwhen data is active on the Ethernet network. If the LAN activity LED is off, makesure that the hub and network are operating and that the correct device driversare 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.If 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 the diagnostic tests did not diagnose the failure or if the server is inoperative, usethe information in this section.If you suspect that a software problem is causing failures (continuous orintermittent), see “Software problems” on page 71.Damaged data in CMOS memory or damaged server firmware can causeundetermined problems. To reset the CMOS data, use the CMOS jumper to clearthe CMOS memory and override the power-on password; see “System-boardswitches and jumpers” on page 16. If you suspect that the server firmware isdamaged, see “Recovering the server firmware” on page 113.If the power supplies are working correctly, complete the following steps:116 IBM System x3250 M3 Types 4251, 4252, and 4261: Problem Determination and Service Guide