It's and old thread. But I think I have an answer for it.
With Android, you just need to check the logs on your machine. When you choose the option to tether the Wifi or mobile data of your phone to your computer, on the logs you will see if the actual connection was made and you're going to have a device name, typically is: usb0.
You can check dmesg. And get something like this.
usbcore: registered new interface driver cdc_ether
rndis_host 1-4:1.0 usb0: register 'rndis_host' at usb-0000:00:1d.7-4, RNDIS devi
ce,
usbcore: registered new interface driver rndis_host
Once you have you have it., do:
sudo udhcpc -i usb0
If problems, check connections on your phone or disconnect usb cable and try again.
This is the usual way I access to the internet with micro core.