Debugging a traditional network is notoriously difficult due to network devices’ heterogeneity and protocols’ decentralized nature, but Software-Defined Networking (SDN) is changing this predicament. Recent works have provided very nice approaches for an administrator to perform several fundamental network tests in a single-domain SDN network. However, how to perform these tests securely in multi-domain networks still remains open. In this paper, we study the highly challenging problem of inter-domain forwarding loop test in a SDN environment. We present two novel testing protocols that can be used for inter-domain loop tests. Both protocols are secure in the sense that they protect each domain's private information about its topology and configuration. The first protocol, based on random sampling, is highly efficient with a small error probability diminishing exponentially in the sample size. The second protocol, based on secure set intersection test, guarantees 100 percent accuracy of the result, although not as efficient as the first one. We provide rigorous proofs for the security and accuracy guarantees, and show our protocols have very good efficiency by testing them with real-world network data.

中文翻译：

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软件定义网络中的安全域间转发环路测试

由于网络设备的异构性和协议的分散性，调试传统网络非常困难，但软件定义网络 (SDN) 正在改变这种困境。最近的工作为管理员在单域 SDN 网络中执行几个基本网络测试提供了非常好的方法。然而，如何在多域网络中安全地执行这些测试仍然是开放的。在本文中，我们研究了 SDN 环境中域间转发循环测试这一极具挑战性的问题。我们提出了两种可用于域间循环测试的新颖测试协议。这两种协议都是安全的，因为它们保护每个域关于其拓扑和配置的私有信息。第一个协议，基于随机抽样，效率很高，错误概率很小，样本量呈指数级递减。第二个协议基于安全集相交测试，保证结果的 100% 准确度，尽管不如第一个有效。我们为安全性和准确性保证提供了严格的证明，并通过使用真实世界的网络数据对其进行测试来证明我们的协议具有非常好的效率。