Security is one of the critical issues in traditional networks. Software-Defined Networking (SDN) improves the security aspect by separating the control plane and the data plane of networks. To improve the performance of SDN, researchers have designed many advanced controller prototypes and considered the controller placement problem. However, link failures are critical security issues in networks and greatly impact SDN’s security. The controller placement problem for link failures is still challenging today. In this paper, we study the SDN controller placement problem for single-link and multi-link failures, respectively. For single-link failures, we develop a heuristic algorithm to address the controller placement problem. For multi-link failures, we introduce the Monte Carlo Simulation to reduce the computational overhead. We conduct experiments with real network topologies, and the simulation results show that the heuristic algorithm can save significantly more time than the optimal algorithm, while achieving good performance.

中文翻译：

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一种用于安全性的稳健 SDN 控制器放置的有效方法

安全是传统网络的关键问题之一。软件定义网络 (SDN) 通过分离网络的控制平面和数据平面来提高安全性。为了提高SDN的性能，研究人员设计了许多先进的控制器原型并考虑了控制器放置问题。然而，链路故障是网络中的关键安全问题，极大地影响了SDN的安全。链路故障的控制器放置问题今天仍然具有挑战性。在本文中，我们分别研究了单链路和多链路故障的 SDN 控制器放置问题。对于单链路故障，我们开发了一种启发式算法来解决控制器放置问题。对于多链路故障，我们引入了蒙特卡罗模拟来减少计算开销。