Finding hard-to-find data plane bugs with a PTA

Bugs in network hardware can cause tremendous problems. However, programmable network devices have the potential to provide greater visibility into the internal behavior of devices, allowing us to more quickly find and identify problems. In this paper, we provide a taxonomy of data plane bugs, and use the taxonomy to derive a Portable Test Architecture (PTA) which offers essential abstractions for testing on a variety of network hardware devices. PTA is implemented with a novel data plane design that (i) separates target-specific from target-independent components, allowing for portability, and (ii) allows users to write a test program once at compile time, but dynamically alter the behavior via runtime configuration. We report 12 diverse bugs on different hardware targets, and their associated software, exposed using PTA.