基于AS关系的BGP路由策略冲突检测研究

对违背AS关系配置原则的路由不稳定性进行研究，提出一种基于AS关系的路由策略冲突检测算法，该算法根据AS关系下的路由策略配置原则，通过把AS关系对象集合与实际导出的AS关系集合比较，发现路由策略冲突，该算法既可用于静态也可用于动态的路由策略冲突检测。     

一种基于AS关系的BGP路由策略冲突检测算法

因特网边界网关协议BGP是基于策略的路由协议，它为路由选择提供了灵活性，然而，实践表面BGP路由会产生振荡，其原因是路由策略配置冲突，通过分析AS关系，提出一种基于AS关系的路由策略冲突检测算法，该算法根据AS关系下的路由策略配置原则检测路由策略配置错误。     

BGP路由策略对路由稳定性的影响分析

在Internet中,域间的路由是由域间路由协议控制的。边界网关协议（BGP）是广泛使用的用于在各个自治系统之间交换网络可达信息的域间路由协议。BGP允许每个自治系统实施各种本地路由策略。用以进行路由的选择和传播。然而,不同的自治系统所制定的本地路由策略可能存在潜在的冲突,从而导致路由的振荡。该文给出了一个BGP的抽象模型,并通过实例分析BGP路由策略对路由稳定性的影响。     

区分自治系统关系的域间路由体系研究

BGP-4是Internet采用的惟一域间路由协议,但它并不能确保路由收敛,复杂的网络结构加剧了路由潜在振荡的危险性．为此,提出了一种自约束的域间选路机制,在不违反传统流量工程原则和自治系统间结算原则的前提下,通过抑制违背自治系统间关系的路由通告和路由选择,达到维护全系统路由稳定的目的;对昕提方案的技术可行性进行论证,给出了新的选路机制原型系统的定义和关键算法的实现．区分自治系统关系的域间路由体系有效回避了路由策略一致性全局检测这一NP-complete问题．     

复杂域间路由体系中自治系统间关系的分类

总结归纳了复杂域间路由体系中自治系统间的互联关系及其行为模式,指出peer-peer和customer-provider关系是当前域间路由的基础,并由此衍生出若干种复杂关系。分析了备种关系的成因,讨论它们的不同实现技术和当前存在的一些技术瓶颈,进一步给出了一种能够识别自治系统关系并自动约束域间路由行为的增强算法。算法兼容RFC1771系列域间路由规范。     

基于IPv6的BGP4+路由策略的研究与实现

边界网关协议(border gateway protocol,BGP)用于在自治系统之间交换路由信息,其目的是在自治系统之间选择最好的路由,BGP为了控制路由的传播为路由附带了大量的属性信息,这些属性信息和路由策略结合起来,在自治系统之间选取更好的路由.介绍了边界网关协议的基础上,重点分析了IPv6下BGP4 路由策略的实现.     

Internet域间路由振荡问题分析与研究

边界网关协议(BGP)是Internet域间路由的事实标准,它允许各自治系统独立配置路由选择和播发策略,但这种局部配置可能导致全局策略配置冲突和低效,从而引起路由振荡的问题。文章分析了域间路由振荡问题,并综述了其相应的各种解决方案。     

受BGP策略影响的路由稳定性仿真数据分析

BGP是一个基于策略的路由协议，目前，由于BGP策略所引发的路由振荡在Internet中非常普遍，给网络稳定性健壮性都带来了很多负面的影响。网络仿真在路由稳定性研究中充当着相当重要的角色。用网络仿真的方法来研究和分析影响BGP路由稳定性的因素，是一个非常科学实用的研究方法和途径。     

未来骨干网路由协议－－BGP

边界网关协议在自治系统之间提供无路径的路由。通常ＢＧＰ在许多ＩＳＰ之间运行。详细介绍ＢＧＰ协议基本框架及如何工作的。     

基于消除竞争环的路由策略冲突检测方法

提出了一种基于消除竞争环的检测路由策略冲突集合的方法，用于在BGP路由发生振荡时，动态地检测导致路由振荡的路由策略冲突。该方法以一种静态描述域间路由语义的形式化方法－－稳定路径问题，作为理论基础；首先利用安全路径矢量协议来识别引发振荡的竞争环，然后以分布的方式查询路由策略对振荡路由的影响，最终以消除竞争环为,目的，来确定路由策略冲突集合。最后，给出了一个仿真实例来说明该方法的执行结果。     

Multi-layer framework for analysing and managing routing configurations

Several research works have shown that the process of Internet routing configuration is error-prone. The primary method used by operators to determine whether their routing configurations are correct is to try them out in operation. A more advanced method is the static analysis of router configurations before they are deployed. We believe that there is a need of broader approaches to verify router configurations automatically and continuously, that is, without human intervention before and after they are deployed. This paper describes a multi-layer analysis framework for configuration checking, which includes three analysis tasks: static analysis before the configuration is deployed; runtime analysis after the configuration is deployed, which is based on routing event monitoring; and active analysis based on checking external information provided by third-parties. We also present the most relevant details of the implementation of our framework.     

Inter-domain collaborative routing (IDCR): Server selection for optimal client performance

Communication between institutions, or domains, residing in the Internet requires a route to be created between the routing domains. Each of these domains is controlled by a single administrative authority, and is referred to as an autonomous system (AS). Control of routes that move the data in the Internet between ASes is problematic. If an AS requires certain route characteristics beyond the selection of the first hop, the AS must pay for some type of special service from its Internet service provider (ISP). The ISP can provide integrity of the data using end-to-end encryption, but the customer AS still does not have control over the route. In other words, an organization is unable to prevent its data from passing through certain parts of the Internet.We believe that a service allowing an AS to select from alternate routes, on behalf of an organization, could meet this need for route customization. The alternate routes could be created to meet the requirements of the source AS, such as the avoidance of another AS. The service must minimize the incremental cost (in hops) of the alternate routes and maximize the probability that an alternate route will be found.We measure the effectiveness of several algorithms as they are used to select ASes to deploy a solution, called inter-domain collaborative routing (IDCR), that allows “friend” routers to collaboratively determine a route. Key to the performance of IDCR is the placement of “friend” routers in the Internet. We explore the trade-off between placing “friend” routers in various levels of the hierarchy of routers in the Internet.In order to measure the effectiveness of IDCR as the set of ASes deploying the service is varied, we track the probability of routing success and monitor the incremental cost in hops as the service creates alternate routes in several small but representative network models. We evaluate three algorithms used to determine which routers should support the IDCR service. The first, called the degree algorithm, categorizes the routers into a hierarchy, based only on the nodal degree of the router [1]. The second, called the factor algorithm, calculates an IDCR factor for each router and uses that to rank select routers to provide the service. Finally, the greedy algorithm, serving as the baseline, iterates across all candidate routers, selecting routers one at a time based on the performance of the service.     

一种通过BGP协议获取精确策略路由表的方法

介绍了BGP路由协议的基本内容，提出了一种结合分析BGP全球路由表的AS-PATH属性与APNIC Whois数据库，获得实时精确的地区级策略路由表的方法，最后对该方法进行实现。     

基于BGP路由策略的仿真建模

针对IP网络上存在的“开环路由”问题,给出了相应的BGP路由策略配置。该配置根据BGP的路由决策进程,结合路由图和访问控制列表的使用,来设置相关的路径属性值,从而对出入自治系统的流量加以控制。给出了具体策略的配置步骤,并用OPNET仿真软件建立模型验证了该策略的有效性。     

一种基于AS关系的路径多样性计算方法

AS(自治系统)关系在因特网中数据传输和路由选择方面起着决定性作用.首先从AS关系角度出发提出了AS多样性的概念,并分析了AS多样性的增长趋势.然后将AS多样性与混联可靠性模型相结合,提出了基于AS关系的路径多样性模型——SPDSA模型及相应的测度.最后,依托虚拟的routeviews多宿主站点,利用SPDSA测度进行了动态的路径多样性实验.实验表明:SPDSA测度优于传统的测度,能够有效地评估多宿主网络环境中的AS路径多样性;多宿主能够显著增加路径多样性;虽然AS多样性增长趋势明显,但近年来AS路径多样性却无明显的变化.     

On the extent of correlation in BGP updates in the Internet and what it tells us about locality of BGP routing events

The Border Gateway Protocol (BGP) is the core routing protocol in the Internet. It maintains reachability information towards IP networks, called prefixes. The adoption of BGP has come at a price: a steady growth in the routing table size (Meng et al., 2005) [1] as well as BGP updates (Cittadini et al., 2010) [2].In this work, we take a different look at BGP updates, by quantifying the amount of prefix correlation in the BGP updates received by different routers in the Internet. We design a method to classify sets of BGP updates, called spikes, into either correlated or non-correlated, by comparing streams of BGP updates from multiple vantage points.Based on publicly available data, we show that a significant fraction of all BGP updates are correlated. Most of these correlated spikes contain updates for a few BGP prefixes only. When studying the topological scope of the correlated spikes, we find that they are relatively global given the limited AS hop distance between most ASs in the Internet, i.e., they propagate at least 2 or 3 AS hops away. Most BGP updates visible from publicly available vantage points are therefore related to small events that propagate across multiple AS hops in the Internet, while a limited fraction of the BGP updates appear in large bursts that stay mostly localised.Our results shed light on a fundamental while often misunderstood aspect of BGP, namely the correlation between BGP updates and how it impacts our beliefs about the share of local and global BGP events in the Internet. Our work differs from the literature in that we try as much as possible to explicitly account in our methodology for the visibility of BGP vantage points, and its implication on the actual claims that can be made from the data.     

在因特网上推导自治系统(AS)相互关系的启发式算法

该文介绍了一个增大的AS图表示法,它将自治系统(AS)的相互关系分类为:客户-供应商关系、兄弟关系、同属关系。同时给出了从BGP路由表中推理出AS相互关系的启发式算法。