A computer implemented method for configuring virtual internal networks for testing is provided, such that affects of testing are internally isolated. The method includes deploying a virtual firewall and deploying a public switch enabling access to an external local area network through a first interface of the virtual firewall. A private switch enabling access to a plurality of virtual machines through a second interface of the virtual firewall is provided. The plurality of virtual machines defines a private network behind the firewall. A network address is assigned to the virtual firewall and a private address is assigned to each of the virtual machines. The plurality of virtual machines is then tested through a test launcher in communication with the public switch.