Linux systems

Enabling 100 full duplex mode on Linux systems.

About this task

Use your primary network interface to enable 100 full duplex mode.

To check if full duplex is enabled:

Procedure

  1. Enter the following command: 
    # dmesg | grep -i duplex

    This should result in output similar to the following:

    eth0: link up, 100Mbps, full-duplex, lpa 0x45E1
  2. Confirm the output contains the words: 
     Full Duplex

    If this is not contained within the output, you must enable full duplex mode. The example output resulting from the command executed in step 1:

    eth0: link up, 100Mbps, full-duplex, lpa 0x45E1

    indicate that the primary network interface is eth0.

    The actions specified in the following process presume that your primary network interface is eth0.

Enabling full duplex mode on Linux

To enable full duplex mode.

Procedure

  1. Open the file ifcfg-eth0, which is contained in: 
      /etc/sysconfig/network-scripts/
  2. Add the ETHTOOL_OPTS setting by adding the following text: 
      ETHTOOL_OPTS="speed 100 duplex full autoneg off"
    Note: The ETHTOOL_OPTS speed setting can be set to either 100 or 1000 depending on speed of connection available 100Mbit/s or 1000Mbit/s (1Gbit/s).