Contrail is an open source software defined networking (SDN) solution from Juniper Networks that provides both a virtual network controller and the ability to configure physical network hardware. It runs on commodity x86 servers, with at least three servers needed for the Contrail controllers and two or more additional servers for the data plane. Contrail can be used to create, modify and manage virtual networks for OpenStack or VMware, as well as control physical top-of-rack switches and other devices.