ValidMaker: A tool for managing device configurations using logical constraints

Configuration Logic (CL) is a formal language that allows a network engineer to express constraints in terms of the actual parameters found in the configuration of network devices. There exists an efficient algorithm that can automatically check a pool of devices for conformance to a set of CL constraints; moreover, this algorithm can point to the part of the configuration responsible for the error when a constraint is violated. A CL validation engine has been integrated into a network management tool called ValidMaker. We show on a simple use case scenario based on Virtual Local Area Networks how representative formal constraints can be expressed with CL and efficiently validated with ValidMaker.