利用BGP虚拟下一跳技术实现IP骨干网流量负载均衡

本文通过更改源BGP路由信息中的Nexthop属性为一个虚拟管理IP地址（虚拟下一跳）,来解决因BGP路由偏向而引起的IP骨干网数据流量的偏向问题,以达到IP骨干网的流量均衡。     

BGP实现网络流量负载分担

BGP是一种自治系统间的动态路由协议,广泛应用于各大电信运营商的核心IP网,它的基本功能是在自治系统间自动交换无环路的路由信息。目前,BGP不仅仅在国家网、省网中使用,许多大型城域网也使用BGP接入省网。众所周知,在自治系统网络内部,通过静态路由或者OSPF等IGP动态路由协议,只要路由器拥有等Metric的多条到达同一网段的路由,路由器就会对到达该网段的流量按照路由链路进行负载分担。在运行BGP的对等自治系统的网络中,如果边界路由器接收到多条到达同一目标网络的BGP路由,BGP最佳路径算法将会选出一条最佳路由,并仅用此路由来…     

MPLS在未来IP网络中的应用设想

分析了MPLS在未来IP网络中的可能的应用前景,认为信息骨干网络可能由光的MPLS和电的MPLS两层网络组成,并完成骨干网上的IP路由,边缘路由器完成边缘的IP路由交换,着重提出了光的MPLS的实现方法和基本原理及结构。     

BGP／MPLSVPN标准化进展

1999年3月，因特网任务工作组(IETF)发布了由Cisco公司提出的RFC2547，描述了一种运营商通过IP骨干网为用户提供虚拟专用网(VPN)业务的方法。该方法使用扩展的BGP(边界路由协议)作为通过运营商的骨干网分发VPN路由信息，使用多协议标记交换(MPLS)在VPN用户站点之间转发VPN流量。提出该方法的主要目的是为了运营商向企业提供企业网外包服务。这种方式对企业非常简单，同时对运营商是可扩展的和灵活的，在提供IP业务的同时提供VPN业务，从而增加收入。     

IP城域网异常流量清洗与阻断技术研究

通过使用BGP协议和PRB技术实现IP城域网异常流量清洗功能,利用虚拟机安装Quagga路由软件向IP城域网下发特定下一跳的BGP路由,实现出向异常流量阻断功能,建成容量清洗系统和近源清洗系统,形成抵御大流量攻击的能力,成功阻止多次重大网络安全事件的发生.     

大型IP互联网设计及路由协议(续)

4 OSPF互联网设计 OSPF是基于IP互联网协议而发展的内部网关协议(IGP)。作为IGP,OSPF在属于同一自治域(AS)的路由器间发送路由信息。一个AS是一组通过普通的路由协议交换路由信息的路由器。OSPF协议基于最短路径优先或链接状态技术。 下列两项设计工作对于成功地实现OSPF非常重要: ·区域网边缘的定义 ·地址分配     

IP网络的服务质量讲座第1讲IP网络的服务质量问题

1“尽力而为”的IP网因特网取得巨大成功的一个重要原因是它所使用的IP的简单性。IP的基本设计原理来自于“端到端”的理念：把“智能”放到网络边缘结点（源和目的主机），留下“傻瓜型”的核心网络。网络核心结点（路由器）除了把IP包的目的地址与转发表对照，确定它的下一跳（hop）并转发外，几乎不需要做任何其他工作。如果下一跳的队列较长，则IP包的转发可能会被延迟；如果下一跳的队列满或不可用，则允许路由器丢弃IP包。因此因特网提供的是一种“尽力而为（besteffort）”的服务，其服务质量是无法预知的。IP的“尽力而为”服…     

IP骨干网BGP路由协议的扩展性

1制约BGP扩展性的几个问题BGP是目前应用在因特网上的IP网络互联协议,为运营商之间的互联提供了稳定而安全的路由协议,具有丰富的路由控制机制。为了更好地控制路由策略,当前大部分的运营商均将BGP部署到骨干路由器。随着网络的不断扩展、路由器数目的增多以及路由信息条目的激增,解决BGP的扩展性问题变得越来越重要。目前BGP的扩展性面临如下几个问题。(1)IBGP的Full-Mesh问题BGP路由协议分为IBGP和EBGP两个部分。IBGP用于自治域内的路由器之间,EBGP用于自治域间的路由器之间。为了防止产生环回路由,BGP要求一个路由器通…     

辽宁联通互联网网络扁平化路由策略研究及实施

辽宁联通网络扁平化建设向层次化和精简化转变,形成一个互操作的、融合的网络结构,各城域网直接与骨干网互连,从而降低设备跳数,减少网络瓶颈和网络延时,在路由策略方面,城域网核心路由器与省网核心路由器建立BGP邻居关系时引入AS过滤策略,城域网不接收来自其他城域网的路由通告,城域网互访流量通过骨干落地路由器转发,省内访问流量通过城域网核心路由器至省网核心路由器的电路实现,统一全省的路由策略。在扁平化后网络应急预案保障中,通过MPLS转发技术,对城域网到IDC拥塞的链路进行流量调整,保障用户上网质量。本文介绍了其路由策略及实施。     

无线宽带多媒体IP网络结构选择

无线IP网的网络结构选择通用无线IP网配置通用无线IP网包括有线的和无线的IP网。IP网由互连的多个子网构成，每个子网拥有唯一的网址。无线IP网由无线接入网和IP骨干网组成。在无线接入网中许多移动终端(MT)都被连接到一个接入点（AP）。每个MT与它的移动主站(MH)相连接，每个MH有一个节点地址，MT还需要一个标识符，例如MAC地址来识别无线接入网中的MT。在由MT和MH构成的综合终端的情况下，IP地址可以用来识别终端实体。所有AP与一个边缘节点（EN）连接，EN具有IP选路由功能，位于IP骨干网的边缘。IP骨干网结构选择IP…     

Scalability Considerations in BGP/MPLS IP VPNs

The scalability of the BGP/MPLS IP VPN solution is one of the main reasons for the wide deployment of this technology. This article first discusses the scaling properties of BGP/MPLS IP VPNs. Then, it explores more advanced topics, such as techniques for scaling the provider edge routers to support a large number of customers and enhancements for reducing the number of VPN route advertisements     

Active networks for efficient distributed network management

The emerging next generation of routers exhibit both high performance and rich functionality, such as support for virtual private networks and QoS. To achieve this, per-flow queuing and fast IP filtering are incorporated into the router hardware. The management of a network comprising such devices and efficient use of the new functionality introduce new challenges. A truly distributed network management system is an attractive candidate to address these challenges. We describe how active network techniques can be used to allow fast and easy deployment of distributed network management applications in IP networks. We describe a prototype system where legacy routers are enhanced with an adjunct active engine, which enables the safe execution and rapid deployment of new distributed management applications in the network layer. This system can gradually be integrated in today's IP network, and allows smooth migration from IP to programmable networks. This is done with an emphasis on efficient use of network resources, which is somewhat obscure by many of today's high-level solutions     

SEAL2: An SDN‐enabled all‐Layer2 packet forwarding network architecture for multitenant datacenter networks

This paper presents the design and development of a new network virtualization scheme to support multitenant datacenter networking (MT‐DCN) based on software‐defined networking (SDN) technologies. Effective multitenancy supports are essential and challenging for datacenter networking designs. In this study, we propose a new network virtualization architecture framework for efficient packet forwarding in MT‐DCN. Traditionally, an internet host uses IP addresses for both host identification and location information, which causes mobile IP problems whenever the host is moved from one IP subnet to another. Unfortunately, virtual machine (VM) mobility is inevitable for cloud computing in datacenters for reasons such as server consolidation and network traffic flow optimization. To solve the problems, we decouple VM identification and location information with two independent values neither by IP addresses. We redefine the semantics of Ethernet MAC address to embed tenant ID information to the MAC address field without violating its original functionality. We also replace traditional Layer2/Layer3 two‐stage routing schemes (MAC/IP) with an all‐Layer2 packet forwarding mechanism that combines MAC addresses (for VM identification and forwarding in local server groups under an edge switch gateway) and multiprotocol label switching (MPLS) labels (for packet transportation between edge switch gateways across the core label switching network connecting all the edge gateways). To accommodate conventional IP packet architecture in a multitenant environment, SDN (OpenFlow) technology is used to handle all this complex network traffics. We verified the design concepts by a simple system prototype in which all the major system components were implemented. Based on the prototype system, we evaluated packet forwarding efficiency under the proposed network architecture and compared it with conventional IP subnet routing approaches. We also evaluated the incurred packet processing overhead caused by each of the packet routing components.     

Survey and taxonomy of IP address lookup algorithms

Due to the rapid growth of traffic in the Internet, backbone links of several gigabits per second are commonly deployed. To handle gigabit-per-second traffic rates, the backbone routers must be able to forward millions of packets per second on each of their ports. Fast IP address lookup in the routers, which uses the packet's destination address to determine for each packet the next hop, is therefore crucial to achieve the packet forwarding rates required. IP address lookup is difficult because it requires a longest matching prefix search. In the last couple of years, various algorithms for high-performance IP address lookup have been proposed. We present a survey of state-of-the-art IP address lookup algorithms and compare their performance in terms of lookup speed, scalability, and update overhead     

基于压缩NH表的高速IP路由查找算法的研究

由于因特网速度不断提高、网络流量不断增加和路由表规模不断扩大,IP路由查找已经成为制约核心路由器性能的主要原因,因而受到了广泛重视.目前人们已经提出几种高速IP路由查找算法,但没有一种是理想的.本文提出一种使用压缩NH表进行IP路由查找的方法,它具有查找速率高、更新时间快、存储代价低、易于实现等特点,能满足10Gbps速率核心路由器环境的要求.     

Strategies Towords Next Generation IP Over Optical Networks

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Comparative study of two CPU router time management algorithms in cellular IP networks

Providing good quality of service (QoS) in cellular IP networks is an important requirement for performance improvement of the cellular IP network. Resource reservation is one of the methods used in achieving this goal and is proven to be effective. The main resources to be reserved in a cellular IP network are bandwidth, buffer and central processing unit (CPU) cycles. Router CPU cycle is the time taken by the router to process the packet of the flow before forwarding it to the next router (hop). This paper proposes a model for CPU cycle optimization of routers for real‐time flows in a cellular IP network. The model applies both genetic algorithm (GA) and particle swarm optimization (PSO) as soft computing tools to optimize the CPU cycles and reduces the flow processing time at each router in the route taken by a flow. Simulation experiments illustrate a comparative study of the model.     

基于HMM的分布式拒绝服务攻击检测方法

文章根据分布式拒绝服务攻击（DDoS）的本质特点，提出了一种基于隐马尔可夫模型（HMM）的DDoS攻击检测方法。该方法通过IP地址信息库．保存当前常用服务的源IP地址，然后对新到数据包的IP地址用HMM建模。通过离线训练，更新IP地址信息库，优化HMM参数。在线检测时，IP地址信息库在线学习更新，HMM实时检测．并根据检测结果通过边界路由器进行积极响应。实验结果显示，该方法具有很好的检测效果，并能及时响应，保持常用服务的延续性。     

Automated provisioning of BGP customers

Manual configuration of IP routers is an expensive, time-consuming, and error-prone process. For large Internet service providers, establishing service for new customers is a major part of the financial cost of running the network. Increasingly, these customers want to exchange routing information with their provider(s) using the border gateway protocol (BGP), a complex and highly programmable interdomain routing protocol. This article describes how a provider can configure its connections to BGP-speaking customers, from the technical questions asked of new customers to the individual configuration commands applied to the production routers. We present a case study of a technical questionnaire and describe how the provider assigns unique identifiers such as IP address blocks, interface names, and access control list numbers on behalf of the customer. Next, we describe an example set of provisioning rules that use the customer-specific information to generate a sequence of configuration commands - a "configlet" - for adding the new connection to the network; our configuration rules are expressed using Cisco Internet Operating System (IOS) commands as an example. Then we describe a database schema for storing and accessing the customer-specific data, and discuss how to use a virtual view on this database to populate a template that captures the syntax of the router commands. Our provisioning system provides an inexpensive, efficient, and accurate way for a provider to configure connections to new BGP-speaking customers.