It turns out that forwarding ports with Cloud9 server only works if the port numbers are the same. So it does work here, but not for the classroom because obviously you can't have the same port number going to both classroom and controller.

I think we should drop the port forwarding, because we are providing a static ip address in both VagrantFiles already, which means we don't have to use :8888 any more, and the whole system works more like EC2. Simple way to move to new system is to edit /etc/hosts and change the entries to point at 10.1.0.2 for the controller.