P-Rex: Fast Verification of MPLS Networks with Multiple Link Failures

P-Rex: Fast Verification of MPLS Networks with Multiple Link Failures

Abstract

Future communication networks are expected to be highly automated, disburdening human operators of their most complex tasks. However, while first powerful and automated network analysis tools are emerging, existing tools provide only limited (and inefficient) support of reasoning about failure scenarios. We present P-Rex, a fast what-if analysis tool, that allows us to test important reachability and policy-compliance properties even under an arbitrary number of failures, in polynomial-time, i.e., without enumerating all failure scenarios (the usual approach today, if supported at all). P-Rex targets networks based on Multiprotocol Label Switching (MPLS) and its Segment Routing (SR) extension and comes with an expressive query language based on regular expressions. It takes into account the actual router tables, and is hence well-suited for debugging. We also report on an industrial case study and demonstrate that P-Rex supports rich queries, performing what-if analyses in less than 70 minutes in most cases, in a 24-router network with over 100,000 MPLS forwarding rules.

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Authors
  • Stenbjerg Jensen, Jesper
  • Beck Krogh, Troels
  • Sand Madsen, Jonas
  • Schmid, Stefan
  • Srba, Jiri
  • Thorgersen, Marc Tom
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Supplemental Material
Shortfacts
Category
Paper in Conference Proceedings or in Workshop Proceedings (Paper)
Event Title
14th International Conference on emerging Networking EXperiments and Technologies (CoNEXT)
Divisions
Communication Technologies
Subjects
Informatik Allgemeines
Event Location
Heraklion/Crete, Greece
Event Type
Conference
Event Dates
December 2018
Date
December 2018
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