RHEL5.5

is_available ()
{
    LC_ALL= LANG= ip -o link | grep -q $1
    [ "$?" = "1" ] || return 0

    alias=$(modprobe -c | awk \
'BEGIN { alias = ""; }
$1 == "alias" && $2 == "'"$1"'" { alias = $3; }
$1 == "install" { install[$2] = $3; }
END {
    cmd = install[alias];
    print alias;
    if (alias == "" || alias == "off" || cmd == "/bin/true" || cmd == ":")
        exit 1;
    exit 0;
}')
    [ $? -eq 0 ] || return 2

    modprobe $1 > /dev/null 2>&1 || {
      return 1
    }
    if [ -n "$HWADDR" ]; then
       local curdev=`get_device_by_hwaddr "$HWADDR"`
       if [ -z "$curdev" ]; then
          return 1
       fi
       rename_device "$1" "$HWADDR" "$curdev"
    fi

    if [ ${alias} == "bonding" ]; then
        install_bonding_driver $1
    fi

    LC_ALL= LANG= ip -o link | grep -q $1
    return $?
}