MD300

São necessários os módulos:

$ /sbin/modprobe usbnet (CONFIG_USB_USBNET=m)
$ /sbin/modprobe cdc_ether (CONFIG_USB_NET_CDCETHER=m)
$ /sbin/modprobe cdc_wdm (CONFIG_USB_WDM=m)
$ /sbin/modprobe cdc_acm (CONFIG_USB_ACM=m)

Adicionar a seguinte regra ao udev:

$ cat << EOF > /etc/udev/rules.d/50-md300.rules
ACTION!="add", GOTO="3G_End"
BUS=="usb", SYSFS{idProduct}=="d0cf", SYSFS{idVendor}=="0fce", PROGRAM="/bin/sh -c 'echo 3 > /sys/%p/device/bConfigurationValue'"
LABEL="3G_End"
EOF

$ sh /etc/rc.d/rc.udev restart