USB to Ethernet adapter

How-to use USB to Ethernet adapters

Tested hardware

SMSC LAN9500

The SMSC LAN9500 is a Hi-Speed USB 2.0 to 10/100 Ethernet Controller. The datasheet can be found here: http://www.smsc.com/media/Downloads_Public/Data_Sheets/9500.pdf. An external EEPROM is used to store the LAN9500 configuration.

Kernel configuration

$ make linux-menuconfig

 Device Drivers  --->
    [*] Network device support  --->
        USB Network Adapters  --->
            [...]
            <M> Multi-purpose USB Networking Framework
            [...]
            <M> CDC Ethernet support
            [...]
            <M> SMSC LAN95XX based USB 2.0 10/100 ethernet devices

Additional tools

In order to read/write the configuration eeprom of the LAN9500, Ethtool has to be used.

# make menuconfig

 Package Selection for the target  --->
    [*] Networking  --->
            [*] ethtool

Usage

First mount the module:

# modprobe smsc95xx

then start the new ethernet port

# ifconfig usb0 192.168.10.208 up

If the message "No EEPROM present" is displayed, this indicates that no configuration file has been detected in the EEPROM. The LAN9500 will start in a default mode and the MAC address will be randomly generated by Linux. The EEPROM can be read/write by using ethtool once the module loaded

 ethtool -e usb0    (eeprom read)
 ethtool -E usb0 magic 0x9500 offset xxx value xxx   (eeprom write value at offset)

Additional informations concerning the EEPROM containt can be found on the SMSC web site.