Towards Consistent SDNs: A Case for Network State Fuzzing

Apoorv Shukla, S. Jawad Saidi, Stefan Schmid, Marco Canini, Thomas Zinner, Anja Feldmann

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


The conventional wisdom is that a software-defined network (SDN) operates under the premise that the logically centralized control plane has an accurate representation of the actual data plane state. Unfortunately, bugs, misconfigurations, faults or attacks can introduce inconsistencies that undermine correct operation. Previous work in this area, however, lacks a holistic methodology to tackle this problem and thus, addresses only certain parts of the problem. Yet, the consistency of the overall system is only as good as its least consistent part. Motivated by an analogy of network consistency checking with program testing, we propose to add active probe-based network state fuzzing to our consistency check repertoire. Hereby, our system, PAZZ, combines production traffic with active probes to periodically test if the actual forwarding path and decision elements (on the data plane) correspond to the expected ones (on the control plane). Our insight is that active traffic covers the inconsistency cases beyond the ones identified by passive traffic. PAZZ prototype was built and evaluated on topologies of varying scale and complexity. Our results show that PAZZ requires minimal network resources to detect persistent data plane faults through fuzzing and localize them quickly while outperforming baseline approaches.
Original languageEnglish (US)
Pages (from-to)1-1
Number of pages1
JournalIEEE Transactions on Network and Service Management
Issue number2
StatePublished - Nov 26 2019

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank Georgios Smaragdakis and our anonymous reviewers for their helpful feedback. This work and its dissemination efforts were conducted as a part of Verify project supported by the German Bundesministerium für Bildung und Forschung (BMBF) Software Campus grant 01IS17052.


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