The increasing demand to provide new network services in a timely and efficient manner is driving the need to design, test and deploy networks quickly and consistently. Testing and verifying at scale is a challenge: network equipment is expensive, requires space, power and cooling, and there is never enough test equipment for everyone who wants to use it! Network virtualization technologies enable a flexible environment for educators, researchers, and operators to create functional models of current, planned, or theoretical networks. This demonstration will show VIRL --- the Virtual Internet Routing Lab --- a platform that can be used for network change validation, training, education, research, or network-aware applications development. The platform combines network virtualization technologies with virtual machines (VMs) running open-source and commercial operating systems; VM orchestration capabilities; a context-aware configuration engine; and an extensible data-collection framework. The system simplifies the process to create both simple and complex environments, run simulations, and collect measurement data.