Validation of SDN policies: a property-based testing perspective

Software-defined networks are being widely adopted and used in large and complex networks supporting critical operations. Their increasing importance highlights the need for effective validation of SDN topologies and routing policies both prior and during operation. The policies that configure an SDN deployment come from several, possibly conflicting sources. This may lead to undesired effects such as node isolation, network partitions, performance drops and routing loops. Such effects can be formulated as automatically testable reusable conditions using property-based testing (PBT). This approach allows to automatically determine and formulate as a counterexample the minimum set of conflicting rules. The approach is especially useful when policies are configured in an incremental manner. PBT techniques are particularly good at automatic counterexample shrinking and have the potential of being extremely effective in this area.