1. A method for simulating computer network devices within a simulated computer network, the method comprising: executing a user interface to present a scenario that includes a set of tasks for a user to complete pertaining to a simulated computer network, the user interface including a network diagram having at least one icon, each icon representing a simulated network device configured according to configuration information; in response to a user selecting one of the icons of the network diagram, executing a simulated network device associated with the selected icon and opening a communication interface between the user and the selected simulated network device; and interpreting commands issued by the user to the selected simulated network device through the communication interface, the selected simulated network device responding to the commands in substantially the same manner as a corresponding actual network device within an actual computer network would respond.