Because you used an SSH tunnel to temporarily establish network-to-Amazon VPC connectivity for your proof of concept environment, you have to add custom properties to your Amazon reservations to ensure the Software bootstrap agent and guest agent run communications through the tunnel.

Network-to-Amazon VPC connectivity is only required if you want to use the guest agent to customize provisioned machines, or if you want to include Software components in your blueprints. For a production environment, you would configure this connectivity officially through Amazon Web Services, but because you are working in a proof of concept environment, you configured a temporary SSH tunnel instead.

Using your fabric administrator privileges, you create a reservation to allocate your Amazon Web Services resources and you include several custom properties to support the SSH tunneling. You also configure the reservation on the same region and VPC as your tunnel machine.