Neighbor-specific BGP: more flexible routing policies while improving global stability
Neighbor-specific BGP: more flexible routing policies while improving global stability
复制标题
邻居特定BGP：更灵活的路由策略，同时提高全局稳定性
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
J. Rexford
中科院分区：
文献类型：
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作者：
Yi Wang;Michael Schapira;J. Rexford
边界网关协议(BGP)为网络管理员提供了相当大的灵活性，可以控制流量如何通过其网络流动。然而，不同自治系统(AS)中的路由策略之间的交互会导致协议振荡。众所周知，BGP全局路由稳定性的充分条件限制了单个AS可以安全实施的局部路由策略的种类。在本文中，我们提出了特定于邻居的BGP(NS-BGP)，它是对BGP的适度扩展，能够在不损害全局稳定性的情况下实现更广泛的本地策略。传统的BGP路由器(针对每个目的地前缀)选择单一的“最佳”路由，而NS-BGP允许路由器代表每个邻居定制路由选择。例如，一个邻居可能更喜欢最短的路由，另一个邻居可能更喜欢最安全的路由，而另一个邻居可能更喜欢最便宜的路由。令人惊讶的是，我们证明了更灵活的NS-BGP保证在路由器如何对候选路由进行排名的限制少得多的条件下是稳定的。我们还证明了增量部署NS-BGP是安全的，因为部分部署NS-BGP的路由系统保证稳定，即使在出现故障和其他拓扑变化的情况下也是如此。除了我们的理论结果之外，我们还描述了NS-BGP如何在不改变BGP消息格式或不需要与相邻AS协作的情况下由单个AS独立部署。
The Border Gateway Protocol (BGP) offers network administrators considerable flexibility in controlling how traffic flows through their networks. However, the interaction between routing policies in different Autonomous Systems (ASes) can lead to protocol oscillation. The best-known sufficient conditions of BGP global routing stability impose restrictions on the kinds of local routing policies individual ASes can safely implement. In this paper, we present neighbor-specific BGP (NS-BGP), a modest extension to BGP that enables a much wider range of local policies without compromising global stability. Whereas a conventional BGP-speaking router selects a single "best" route (for each destination prefix), NS-BGP allows a router to customize the route selection on behalf of each neighbor. For example, one neighbor may prefer the shortest route, another the most secure route, and yet another the least expensive route. Surprisingly, we prove that the much more flexible NS-BGP is guaranteed to be stable under much less restrictive conditions on how routers "rank" the candidate routes. We also show that it is safe to deploy NS-BGP incrementally, as a routing system with a partial deployment of NS-BGP is guaranteed to be stable, even in the presence of failure and other topology changes. In addition to our theoretical results, we also describe how NS-BGP can be deployed by individual ASes independently without changes to the BGP message format or collaboration from neighboring ASes.