etc/dnsmasq.d/99-no-default-route - usb-gadget - Git at Google

 # Prevent advertising our device as the default gateway.
 #
 # This prevents mis-routing of packets to the device, which causes it to act
 # like a black hole.

 dhcp-option=3
	# Prevent advertising our device as the default gateway.
	#
	# This prevents mis-routing of packets to the device, which causes it to act
	# like a black hole.

	dhcp-option=3