ethtool I/O error with netxen_nic in RHEL 5

Issue

• When trying to set the speed/duplex/autoneg on a NX3031 using netxen_nic, an I/O error is thrown:

  # ethtool -s eth0 speed 100 duplex full autoneg off
  Cannot set new settings: Input/output error
    not setting speed
    not setting duplex
    not setting autoneg