Putting network verification to good use.

The past decade has witnessed remarkable progress in the field of network verification, and interest from academia and industry has spurred the development of increasingly sophisticated verification tools and algorithms. However, outside of a handful of large cloud computing providers, the use of network verification is still sparse. We argue that the next frontier for network verification is to enable easy and effective use by "average" network engineers. Whereas in software development, practitioners frequently use testing frameworks to describe the expected behavior of their systems and to measure the effectiveness of their tests through metrics such as code coverage, no such frameworks exist for the equally challenging task of designing and maintaining networks. To address this gap, we outline the design of a network verification framework. In doing so, we propose 1) a method to compute test coverage for networks, which tells engineers how well their invariants are testing the network; and 2) a new declarative invariant language that makes it easy to express network invariants and enables computation of coverage metrics.