After you plug in the tablet and enable tethering, you should be able to see the interface with
> ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
link/ether b8:27:eb:2c:bd:8c brd ff:ff:ff:ff:ff:ff
3: usb0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether a2:c2:f2:2c:9d:30 brd ff:ff:ff:ff:ff:ff
On a raspbian pi it will almost certainly be
usb0. That's that.
If it's not there and
modprobe cdc_ether fails, keep reading.
There is some kernel configuration that's critical to this; using the default raspbian should be fine, but if you've rolled your own you need the following options under Device Drivers -> Network Device Support -> USB Network Adapters:
- Multi-purpose USB Networking Framework. This enables some more options, but chances are you already have it and SMSC LAN95XX based USB 2.0 10/100 ethernet devices enabled since that's required for basic ethernet on the pi. To this you must add:
- CDC Ethernet support
- CDC EEM support
- CDC NCM support
- Host for RNDIS and ActiveSync devices
- Simple USB Network Links (CDC Ethernet subset). This has suboptions of its own; Embedded ARM Linux links (iPaq, ...) is then required.
These can be added as modules but when I did this using my last build tree (generally that's fine, you're just adding a module) they still refused to load; I had to rebuild the kernel as well. They now autoload when I plug in a device and enable tethering.