Batfish An open source network configuration analysis tool
Batfish finds errors and guarantees the correctness of planned or current network configurations. It enables safe and rapid network evolution, without the fear of outages or security breaches. Batfish was originally developed by researchers at Microsoft Research, UCLA, and USC. Many others have since contributed to it. It is currently maintained by Intentionet, who also offers Batfish Enterprise, a service that extends and enhances the core capabilities of Batfish.
Find out more about the project over here.