We propose a new environment for testing the behavior of TCP. We analyze existing test methodologies and show that there is still a need to reduce the loads imposed on both the worker and the expert. The Auto Detector is extensible and so well supports both the automation of predefined tasks and the communication tools needed to ensure gradual refinement by the participants. To show the effectiveness of our proposal, actual software flaws found in HP/UX and the Windows operating system are taken as examples of how to realize the automation of reproduction and detection tasks; it is flexible enough to resolve real-world issues.