Understanding Route Redistribution
Understanding Route Redistribution
复制标题
了解路由重分配
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Hui Zhang
中科院分区：
文献类型：
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作者：
Franck Le;G. Xie;Hui Zhang
路由重分配（RR）已成为IP网络设计的一个组成部分，因为越来越需要跨路由协议边界传播某些路由。虽然RR被广泛使用，并且在几个重要方面与BGP相似，但令人惊讶的是，网络社区尚未系统地研究RR的安全性。本文提出了第一个分析模型，了解网络范围内的路由动态和评估的安全性，一个特定的RR配置的RR的影响。我们首先说明如何容易不准确的配置RR可能会导致严重的路由不稳定性，包括路由振荡和持久的路由环路。与此同时，提供了关于这些不稳定性的根本原因的一般性意见。然后，我们介绍了一个正式的模型的基础上，一般的意见，代表和研究的安全路线重新分配。使用该模型，我们证明了给定的RR配置，确定是否在一个周期的再分配结果是NP-难的。考虑到这种复杂性，我们提出了一个充分条件，可以在多项式时间内检查与建议的分析模型，以确保安全的RR配置。最后，本文提出了对当前RR协议的潜在更改，以保证安全性。
Route redistribution (RR) has become an integral part of IP network design as the result of a growing need for disseminating certain routes across routing protocol boundaries. While RR is widely used and resembles BGP in several nontrivial aspects, surprisingly, the safety of RR has not been systematically studied by the networking community. This paper presents the first analytical model for understanding the effect of RR on network wide routing dynamics and evaluating the safety of a specific RR configuration. We first illustrate how easily inaccurate configurations of RR may cause severe routing instabilities, including route oscillations and persistent routing loops. At the same time, general observations regarding the root causes of these instabilities are provided. We then introduce a formal model based on the general observations to represent and study the safety of route redistribution. Using the model, we prove that given a RR configuration, determining whether the redistributions result in a cycle is NP-hard. Given this complexity, we present a sufficient condition, which can be checked in polynomial time with the proposed analytical model, for ensuring the safety of a RR configuration. Finally, the paper proposes potential changes to the current RR protocol to guarantee safety.