Towards passive analysis of anycast in global routing: unintended impact of remote peering
Towards passive analysis of anycast in global routing: unintended impact of remote peering
复制标题
对全球路由中的任播进行被动分析：远程对等互连的意外影响
DOI：
10.1145/3371927.3371930
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Chase Cotton
中科院分区：
文献类型：
--
作者：
Rui;Shuai Hao;Haining Wang;Amogh Dhamdere;A. Dainotti;Chase Cotton
Anycast已被当今的互联网服务广泛采用，包括DNS、CDN和DDoS保护，即从分布式位置通告相同的IP地址，并将客户端定向到拓扑最近的服务副本。以前的研究集中在选播的各个方面，要么是它在特定服务(如DNS)中的使用，要么是它被互联网范围内的主动探测方法采用的特征。在本文中，我们首先探索了一种基于先前收集的全局BGP路由信息来表征任播的替代方法。利用最先进的主动测量结果作为接近地面的真相，我们的被动方法不需要任何互联网范围的探测器，可以达到90%的准确率检测任播前缀。更重要的是，我们的方法揭示了基于活动测量的先前数据集错过的任播前缀。在调查不准确的根本原因时，我们发现任播路由已经与越来越多地采用远程对等(远程对等)纠缠在一起，远程对等是一种第2层互连类型，其中IP网络可以远程对等于IXP，而无需物理地出现在IXP。来自第3层的远程对等的不可见性打破了BGP上最短AS路径的假设，并对任播性能造成了意外影响。我们从BGP路由信息中识别出这样的情况，并观察到至少19.2%的任播前缀已经受到远程对等的潜在影响。
Anycast has been widely adopted by today's Internet services, including DNS, CDN, and DDoS protection, in which the same IP address is announced from distributed locations and clients are directed to the topologically-nearest service replica. Prior research has focused on various aspects of anycast, either its usage in particular services such as DNS or characterizing its adoption by Internet-wide active probing methods. In this paper, we first explore an alternative approach to characterize anycast based on previously collected global BGP routing information. Leveraging state-of-the-art active measurement results as near-ground-truth, our passive method without requiring any Internet-wide probes can achieve 90% accuracy in detecting anycast prefixes. More importantly, our approach uncovers anycast prefixes that have been missed by prior datasets based on active measurements. While investigating the root causes of inaccuracy, we reveal that anycast routing has been entangled with the increased adoption of remote peering, a type of layer-2 interconnection where an IP network may peer at an IXP remotely without being physically present at the IXP. The invisibility of remote peering from layer-3 breaks the assumption of the shortest AS paths on BGP and causes an unintended impact on anycast performance. We identify such cases from BGP routing information and observe that at least 19.2% of anycast prefixes have been potentially impacted by remote peering.