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Resolving suspected Ethernet controller problems

The method that you use to test the Ethernet controller depends on which operating system you are using. See the operating-system documentation for information about Ethernet controllers, and see the Ethernet controller device-driver readme file.

Complete the following steps to attempt to resolve suspected problems with the Ethernet controller.

  1. Make sure that the correct device drivers, which come with the server are installed and that they are at the latest level.
  2. Make sure that the Ethernet cable is installed correctly.
    • The cable must be securely attached at all connections. If the cable is attached but the problem remains, try a different cable.
    • Make sure that the cable rating is applicable for the network speed selected. For example, an SFP+ cable is only suitable for 10G operation. An SFP25 cable is needed for 25G operation. Likewise for Base-T operation, a CAT5 cable is required for 1G Base-T operation while a CAT6 cable is required for 10G Base-T operation.

  3. Set both the adapter port and the switch port to auto-negotiation. If auto-negotiation is not supported on one of the ports, try configuring both ports manually to match each other.
  4. Check the Ethernet controller LEDs on the adapter and server. These LEDs indicate whether there is a problem with the connector, cable, or hub.

    Although some adapters may vary, when installed vertically the adapter link LED is typically on the left of the port and the activity LED is typically on the right.

    The server front panel LED is described in System LEDs and diagnostics display.

    • The Ethernet link status LED is lit when the Ethernet controller receives a link indication from the switch. If the LED is off, there might be a defective connector or cable or a problem with the switch.
    • The Ethernet transmit/receive activity LED is lit when the Ethernet controller sends or receives data over the Ethernet network. If the Ethernet transmit/receive activity is off, make sure that the hub and network are operating and that the correct device drivers are installed.
  5. Check the Network activity LED on the server. The Network activity LED is lit when data is active on the Ethernet network. If the Network activity LED is off, make sure that the hub and network are operating and that the correct device drivers are installed.

    Network activity LED location is specified in Troubleshooting by system LEDs and diagnostics display.

  6. Check for operating-system-specific causes of the problem, and also make sure that the operating system drivers are installed correctly.
  7. Make sure that the device drivers on the client and server are using the same protocol.
If the Ethernet controller still cannot connect to the network but the hardware appears to be working, the network administrator must investigate other possible causes of the error.