• disable usb0 nic RHEL5

    Linux, Networking 02-03-2012 Comments Off

    The usb0 NIC sometimes causes problems with certain Oracle grid components on 11g RAC.

    Setting the /etc/sysconfig/network-scripts/ifcfg-usb0 ‘ONBOOT=no’ does not always work and the devices fires up again.

    You can disable the NIC from even initializing by adding the following as the first line in /etc/udev/rules.d/60-net.rules
    ACTION==”add”, DRIVER==”usb”, SYSFS{configuration}==”CDC Ethernet”, OPTIONS+=”ignore_device, last_rule”

  • Set ethtool options in ifcfg-ethX file

    HEADS UP, Linux, Networking 06-14-2011 Comments Off

    ETHTOOL_OPTS=”autoneg off speed 100 duplex full”

  • Script to check link on each interface on a bonded connection

    Linux, Networking 10-08-2010 Comments Off 
    for mac in `ifconfig | grep bond| awk '{print $5}'`;
do
  echo;
  echo "Checking interfaces bound to MAC: $mac ...";
  for interface in `ifconfig | grep $mac | grep -v ^bond | awk '{print $1}'`;
  do
    echo -n "$interface: "; ethtool $interface | grep Link; echo;
  done;
done

    will display result similar to:

    Checking interfaces bound to MAC: 00:0D:60:98:16:38 …
    eth0:   Link detected: yes

    eth2:   Link detected: yes

    Checking interfaces bound to MAC: 00:0D:60:98:16:39 …
    eth1:   Link detected: yes

    eth3:   Link detected: yes

  • Linux bonded NICs

    Networking 09-06-2010 Comments Off

    http://www.cyberciti.biz/tips/linux-bond-or-team-multiple-network-interfaces-nic-into-single-interface.html