Rule-level Data Plane Monitoring With Monocle

We present Monocle, a system that systematically monitors the network data plane, and verifies that it corresponds to the view that the SDN controller builds and tries to enforce in the switches. Our evaluation shows that Monocle is capable of fine-grained per-rule monitoring for the majority of rules. In addition, it can help controllers to cope with switches that exhibit transient inconsistencies between their control plane and data plane states.