Setup the Ethernet gadget of PI Zero with dnsmasq

Sometimes it makes sense to connect to the PI Zero by using the g_ether kernel module. This connection is way more reliable than the WiFi connection in certain environments.

The setup is quite simple. dnsmasq will provide a local DHCP and DNS server.

echo “dtoverlay=dwc2” | sudo tee -a /boot/config.txt
Edit /boot/cmdline.txt and add modules-load=dwc2,g_ether after rootwait
sudo apt install dnsmasq
Edit /etc/network/interfaces and add the following:

auto usb0
iface usb0 inet static
      address 192.168.44.1/24

You can also disable the wlan0 interface by removing all the lines which mention it to disable wlan.

Edit /etc/dnsmasq.conf and add the following:

listen-address=192.168.44.1
dhcp-range=192.168.44.10,192.168.44.20,12h

sudo systemctl enable --now dnsmasq

After a reboot of the PI you should see that the Ethernet Gadget on the connected USB host.

If you have trouble connecting it check the following:

Did you use the correct USB port on the PI Zero? Only one offers the possibility to transfer data.
Try to reload the kernel module: sudo modprobe -r g_ether && sudo modprobe g_ether
Is a firewall on the PI blocking the DHCP client?

Additional information on OTG:

HowToOTG.md