A method and system to capture and playback network activity are disclosed. The system comprises a recorder to continuously record data directly from a live network over a selected period of time. The system also comprises a simulator to create a simulated network based on the data recorded by the recorder, so that a network management application can be run against the simulated network. Conveniently, the system further comprises a selector to allow a user to identify at least one network device that is to be recorded. The selector may also be used to allow the user to specify the network device's parameters and/or properties that are to be recorded by the recorder, and to select the period of time that the recorder is to continuously record data from the live network.