- `headless` (bool) - Packer defaults to building VirtualBox virtual machines by launching a GUI that shows the console of the machine being built. When this value is set to true, the machine will start without a console. - `vrdp_bind_address` (string) - The IP address that should be binded to for VRDP. By default packer will use 127.0.0.1 for this. If you wish to bind to all interfaces use 0.0.0.0. - `vrdp_port_min` (int) - The minimum and maximum port to use for VRDP access to the virtual machine. Packer uses a randomly chosen port in this range that appears available. By default this is 5900 to 6000. The minimum and maximum ports are inclusive. - `vrdp_port_max` (int) - VRDP Port Max