Abstract interpretation of distributed network control planes

Abstract

The control plane of most computer networks runs distributed routing protocols that determine if and how traffic is forwarded. Errors in the configuration of network control planes frequently knock down critical online services, leading to economic damage for service providers and significant hardship for users. Validation via ahead-of-time simulation can help find configuration errors but such techniques are expensive or even intractable for large industrial networks. We explore the use of abstract interpretation to address this fundamental scaling challenge and find that the right abstractions can reduce the asymptotic complexity of network simulation. Based on this observation, we build a tool called ShapeShifter for reachability analysis. On a suite of 127 production networks from a large cloud provider, ShapeShifter provides an asymptotic improvement in runtime and memory over the state-of-the-art simulator. These gains come with a minimal loss in precision. Our abstract analysis accurately predicts reachability for all destinations for 95% of the networks and for most destinations for the remaining 5%. We also find that abstract interpretation of network control planes not only speeds up existing analyses but also facilitates new kinds of analyses. We illustrate this advantage through a new destination "hijacking" analysis for the border gateway protocol (BGP), the globally-deployed routing protocol.

Enhanced Logical Representations of a Real Network Based on an Algebraic Model

“…Then, the time of verification programming may be out of control. Though some tools aim to improve the efficiency of verifying the reachability of the network by compressing the scale of the large network [19] or abstracting the control plane in a systematic form [15], they are obviously at the cost of losing the possibility of verifying QoS network properties. Therefore, it is still a significant and challenging issue to model and encode the network concisely and concretely.…”

“…Some related work is enriched by properties that combine its elements, allowing stronger statements about protocol convergence to emerge and permitting a computationally easy characterization of free cycles. Motivated by previous work [1], [10], [14], [15], we modify the routing algebra to combine routing records with basic algebraic structure, which is more helpful to verify the network properties. For ease of encoding and computing, we assume that the network is already convergent.…”

A General Framework for Compositional Network Modeling

“…Computing with sets. Many network analyses reason about sets of objects [4,5,22,41] Once a user creates a transformer, Zen can automatically compute the TransformForward set that represents the set of output objects that correspond to the given input objects and TransformReverse set that represents the set of input objects that correspond to the given output objects. These capabilities enable users to build efficient analyses without worrying about the implementation.…”

“…There has been a long line of research on network verification. These works differ in terms of verification algorithms used as well as the network functionality targeted: stateless dataplanes [19, 21-23, 29, 40, 41], stateful dataplanes (e.g., middleboxes) [32,43], programmable dataplanes (e.g., Click, P4) [9,28,35], distributed routing protocols (e.g., BGP, OSPF) [3][4][5][10][11][12], and centralized control planes [6,15]. While different domains come with their own challenges, they commonly employ translations to standard verification technologies.…”

Aed

“…Devices in the same role have the same configuration template, and configuration similarity is violated if a device's configuration deviates from its template. For example, filters are often copied verbatim across devices with the same role [9,14]. If the filters of one device are modified-i.e.…”