auto tun0
iface tun0
	gre-local 203.0.113.2
	gre-remote 203.0.113.1
	gre-dev eth0
	gre-ttl 255
	gre-flags nopmtudisc ignore-df
	address 203.0.113.10/30
	gateway 203.0.113.9

iface eth0
	address 203.0.113.2/30