root@turris:~# cat /root/openvpn-setup-script

#!/bin/sh
table="table 103"
unreachable="unreachable"
metric="metric 10"

case $script_type in
route-up)
        unreachable=""
	via="via $route_vpn_gateway"
	#via="via $route_vpn_gateway dev $dev"
	src="src $ifconfig_local"
	;;
*)
	via=""
	src=""
	;;
esac
/sbin/ip route replace $unreachable default $via $table $src $metric