Mechanical Investigation of Packet Production

Networks are getting larger and more complex, yet administrators rely on rudimentary tools such as ping and trace route to debug problems. ATPG propose an automated and systematic approach for testing and debugging networks called “Automatic Test Packet Generation” (ATPG). ATPG reads router configurations and generates a device-independent model. The model is used to generate a minimum set of test packets to minimally exercise every link in the network or maximally exercise every rule in the network. Test packets are sent periodically, and detected failures trigger a separate mechanism to localize the fault. ATPG can detect both functional and performance problems . ATPG complements but goes beyond earlier work in static checking which cannot detect liveness or performance faults or fault localization which only localize faults given liveness results. ATPG describe our prototype implementation and results on two real-world data sets: Stanford University's backbone network and Internet2. We find that a small number of test packets suffice to test all rules in these networks. ATPG code and the data sets are publicly available.