Network troubleshooting with Mirror VNets

Today diagnosing problems, deploying new services, testing protocol interactions, or validating network configurations are still largely unsolved problems for both enterprise and Internet Service Provider (ISP) networks. Due to the intrinsically distributed nature of network state, frequent timing dependencies, and sources of non-determinism involved, any change may introduce undesired effects-even the impact of a simple configuration change can be hard to predict. In this paper we show how to leverage network virtualization to improve our debugging ability: By replicating and cloning production networks and then applying the changes to the cloned network in a safe fashion. Mirror VNets thus enable troubleshooting as well as safe upgrades to both software and configuration.