The inherent complexity in today's networks means humans are simply incapable of reasoning about its correctness. Yet network engineers are asked to do so on a daily basis. It is no surprise then that we consistently see headlines such as “Comcast Suffers Outage Due to Significant Level 3 BGP Route Leak” or “Google accidentally broke Japan's Internet”. Fortunately, recent advances in network validation, specifically control plane validation, can provide strong guarantees on the correctness of network configuration and completely prevent such errors.
Using network validation tools like Batfish, network engineers can make configuration changes without taking down the Internet, making headlines like those above a thing of the past.