3,893 research outputs found
Packet flow analysis in IP networks via abstract interpretation
Static analysis (aka offline analysis) of a model of an IP network is useful
for understanding, debugging, and verifying packet flow properties of the
network. There have been static analysis approaches proposed in the literature
for networks based on model checking as well as graph reachability. Abstract
interpretation is a method that has typically been applied to static analysis
of programs. We propose a new, abstract-interpretation based approach for
analysis of networks. We formalize our approach, mention its correctness
guarantee, and demonstrate its flexibility in addressing multiple
network-analysis problems that have been previously solved via tailor-made
approaches. Finally, we investigate an application of our analysis to a novel
problem -- inferring a high-level policy for the network -- which has been
addressed in the past only in the restricted single-router setting.Comment: 8 page
Diagnose network failures via data-plane analysis
Diagnosing problems in networks is a time-consuming and error-prone process. Previous tools to assist operators primarily focus on analyzing control
plane configuration. Configuration analysis is limited in that it cannot find
bugs in router software, and is harder to generalize across protocols since it
must model complex configuration languages and dynamic protocol behavior.
This paper studies an alternate approach: diagnosing problems through
static analysis of the data plane. This approach can catch bugs that are
invisible at the level of configuration files, and simplifies unified analysis of a
network across many protocols and implementations. We present Anteater, a
tool for checking invariants in the data plane. Anteater translates high-level
network invariants into boolean satisfiability problems, checks them against
network state using a SAT solver, and reports counterexamples if violations
have been found. Applied to a large campus network, Anteater revealed 23
bugs, including forwarding loops and stale ACL rules, with only five false
positives. Nine of these faults are being fixed by campus network operators
Applying Formal Methods to Networking: Theory, Techniques and Applications
Despite its great importance, modern network infrastructure is remarkable for
the lack of rigor in its engineering. The Internet which began as a research
experiment was never designed to handle the users and applications it hosts
today. The lack of formalization of the Internet architecture meant limited
abstractions and modularity, especially for the control and management planes,
thus requiring for every new need a new protocol built from scratch. This led
to an unwieldy ossified Internet architecture resistant to any attempts at
formal verification, and an Internet culture where expediency and pragmatism
are favored over formal correctness. Fortunately, recent work in the space of
clean slate Internet design---especially, the software defined networking (SDN)
paradigm---offers the Internet community another chance to develop the right
kind of architecture and abstractions. This has also led to a great resurgence
in interest of applying formal methods to specification, verification, and
synthesis of networking protocols and applications. In this paper, we present a
self-contained tutorial of the formidable amount of work that has been done in
formal methods, and present a survey of its applications to networking.Comment: 30 pages, submitted to IEEE Communications Surveys and Tutorial
A semantic approach to reachability matrix computation
The Cyber Security is a crucial aspect of networks management. The Reachability Matrix computation is one of the main challenge in this field. This paper presents an intelligent solution in order to address the Reachability Matrix computational proble
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