sharing network over usb at boot

BeagleBone Black running Debian connected to Windows 8 PC via USB. Following the instructions in http://stackoverflow.com/questions/19481415/share-the-internet-access-from-laptop-to-beaglebone-black-and-then-access-it-thr I got BBB to connect to the internet.

The issue is that I can not figure out how to get the route added at boot.

I added /sbin/route add default gw 192.168.7.1 into /etc/rc.local before the exit 0 but then systemctl reports that rc.local.service failed and the route does not get added. I verified that putting something like /bin/ps aux > /tmp/foo.bar works correctly in /etc/rc.local

Adding /sbin/route … to the .profile for root works correctly when I ssh in to root.

Thank you for any help.
Mike.