策略路由在多出口校园网中的灵活应用

文章分析了校园网多出口的需求及面临的问题,指出目前常用的基于网络地址转换(NAT)的校园网多出口路由策略存在的缺陷,提出了一种结合网络地址转换、路由策略、策略路由等多种技术的多出口配置方案。并结合校园网实例实现了具体应用,实践证明该方案通过策略路由技术的灵活应用,满足了多校区多出口校园网的各种应用需求。     

校园网的路由策略选择及实现

校园网出口带宽不足已成为众多高校面临的严重问题，为了解决问题，我们提出了增加一条接入链路和一台路由器的方案，利用基于策略路由、静态路由选择和网络地址翻译（NAT）等技术，有效解决了网络瓶颈问题，在合理利用现有CERNET网络资源的同时，还可使用当地网络服务提供商（ISP）提供的带宽高速安全地上网。     

基于Linux系统的校园网多出口策略路由实现

校园网有多个出口时,出口路由设备对服务器发出的数据包必须要进行策略路由处理.提出基于Linux系统的校园网多出口策略路由实现方案,通过在路由处理前检查连接跟踪的信息,更细致地区分校园网内服务器发出的数据包,对校园网发出的数据包进行正确的路由处理,比仅仅依靠源地址判断的策略路由实现更灵活和方便.     

用户自主选择的校园网出口策略路由实现

校园网有多个出口时,出口路由设备必须要对校内IP发出的数据分组进行策略路由处理,才能保证正常的通信。传统由网络管理员设置的源地址策略路由灵活性不够,无法满足用户多样变化的需求。因此提出由用户根据使用需要,自主选择所用IP地址的策略路由,在网络出口设备上对校园网发出的数据包进行正确的路由处理,实现更灵活和方便的校园出口策略路由。通过10年校园网的实际使用,证明该方式能满足用户的各种需求,运行稳定可靠。     

校园网与本地ISP接入网之间的互联互通

本文介绍了通过网络地址转换和策略路由方法，实现校园网与校园内其他ISP接入网之间的互联，给出了互联方案和配置方法，并以AVAYA P882和CISCO CATALYST 6000交换机为例，详细给出了具体的实现。     

基于GLBP和IP SLAs协议的多出口路由方法

针对校园网多出口的需求和遇到的问题,通过对比几种现有方法,提出了以GLBP协议和IP SLAs配合策略路由(PBR)及网络地址翻译(NAT)的解决方案.该方案整合了CERNET和本地ISP的网络资源优势,实现了链路故障和拥塞时的自动切换,提高了访问速度和链路使用效率.     

多出口服务访问技术的研究与实现

在校园网多出口的拓扑结构中,以智能解析技术为基础,同时采用了策略路由和地址转换等关键技术,从而提出并实现了对外服务访问的解决方案.该方案有效地解决了内外网互相访问的速率和可靠性问题,提高了网络效率.     

策略路由在校园网中的应用

随着校园网用户数量和各种网络业务在互联网上的不断增长,互联网出口带宽不足已成为高校信息化发展面临的一个重要问题,为此笔者所在单位对校园网接入带宽进行了升级改造,在原有出口带宽基础上增加一条线路,以解决出口带宽不足的问题。通过在相关网络设备上利用路由策略为校内多个区域用户分配出口线路,实现了高效、合理地利用出口带宽资源。本文通过问题的引入、策略路由的概述、具体应用策略路由等几个方面阐述了在核心路由器进行合理的策略路由设置,解决了双线接入的流量分流问题,更加有效的利用了网络资源。     

多线ISP链路出口的边界网设计

根据中山大学校园网边界网的实际情况,阐述在多线ISP链路出口环境下的路由选择、源网络地址转换、精细化流量管理、逆向代理及基于边界系统的智能域名解析等技术,从而提出一种合理的大规模校园网多线ISP链路出口解决方案。     

基于策略路由解决服务器对外访问的设计方案

在双出口的校园网拓扑结构中，基于策略路由解决校园网服务器对外访问的问题，并提供设计方案。     

基于策略路由的高校校园网络多出口配置

由于不同网络运营商之间的互联互通问题,造成网络用户访问接入在不同运营商线路上的服务器资源时,速度大受影响,甚至无法访问。为满足高校校园网络用户能利用校园网线路访问校外资源信息的速度能达到要求,实现资源共享的目的,提出基于策略路由的网络多出口配置方案,以解决网络出口数据按不同的访问目标途经不同的线路,实现各行其道,一方面提高网络的访问速度,另一方面提高网络的安全性。     

RouterOS软件路由器在校园网中的应用研究

RouterOS路由系统,具有强大的VLAN管理、无线、用户认证、策略路由、VPN、带宽控制和防火墙功能,研究RouterOS在校园网络中的应用具有十分重要的意义.     

Multi‐topology routing based egress selection approach to achieve hybrid intra‐AS and inter‐AS traffic engineering

Hot‐potato routing is a border gateway protocol policy that selects the ‘closest’ egress router in terms of interior gateway protocol cost. This policy imposes inherent interactions between intra‐AS (Autonomous System) and inter‐AS traffic engineering. In light of this observation, we present a hybrid intra‐AS and inter‐AS traffic engineering scheme named egress selection based upon hot potato routing. This scheme involves link weight optimization, which can not only minimize the time that IP (Internet Protocol) packets travel across the network by assigning specified egress router but also balance the load among the internal links of the transit network. Egress selection based upon hot potato routing also incorporates multi‐topology routing technique to address the problem that one set of link weights might not guarantee specified egress routers. Accordingly, we formulate the link weights optimization problem using multi‐topology routing as a mixed integer linear programming model. And we present a new heuristic algorithm to make the problem tractable. Numerical results show that only a few topologies are needed to guarantee specified egress router, and maximum link utilization is also reduced. Copyright © 2014 John Wiley & Sons, Ltd.     

基于策略的MPLS网络传送控制技术分析

分析了基于多协议标记交换(MPLS)可管可控网络的体系结构。论述了业务优先级策略、带宽策略和降级策略3种传送控制支持的策略。提出了用于业务优先级策略的策略条件最大匹配算法。对基于策略的MPLS通信网络的传送控制工作原理进行了阐述,并进行了实验验证。实验证明基于策略的MPLS通信网络传送控制方法可行、有效。     

Multipath inter-domain routing for named data networking

To facilitate content retrieval among NDN domains,a multipath inter-domain routing for named data networking(MIRNDN)was proposed.Under MIRNDN,an AS(autonomous system)maintained merely the routing state of content reachable from its own network or from its customers’ networks and aggregated routing information to mitigate routing scalability issue; “valley free”routing policy was applied to guide Interest packets that solicit content unreachable from the AS’s own network nor from its customers’ networks to explore matching data packets via multiple paths,and NDN’s requests aggregation,in-network caching and adaptive forwarding optimized such exploration; the reachability information of content from multiple paths was collected to support Interest multipath forwarding.The properties of FIB size and the convergence time and communication cost of routing update under MIRNDN were analyzed in theory.The experimental results in the AS level topology of current Internet validates that MIRNDN mitigates the scalability issue of NDN inter-domain routing,has relative short convergence time and moderate communication cost for routing update,and effectively reduces unnecessary Interest forwarding.     

TIE Breaking: Tunable Interdomain Egress Selection

In a large backbone network, the routers often have multiple egress points they could use to direct traffic toward an external destination. Today's routers select the ldquoclosestrdquo egress point, based on the intradomain routing configuration, in a practice known as early-exit or hot-potato routing. In this paper, we argue that hot-potato routing is restrictive, disruptive, and convoluted and propose an alternative called TIE (Tunable Interdomain Egress selection). TIE is a flexible mechanism that allows routers to select the egress point for each destination prefix based on both the intradomain topology and the goals of the network administrators. In fact, TIE is designed from the start with optimization in mind, to satisfy diverse requirements for traffic engineering and network robustness. We present two example optimization problems that use integer-programming and multicommodity-flow techniques, respectively, to tune the TIE mechanism to satisfy networkwide objectives. Experiments with traffic, topology, and routing data from two backbone networks demonstrate that our solution is both simple (for the routers) and expressive (for the network administrators).     

Dynamic Policy-Based Network Management for a Secure Coalition Environment

This article reports the latest results of an R&D effort to develop a prototype implementation of a dynamic policy-based network management (PBNM) system that can be used to configure and manage a secure network for a coalition environment across an unsecured wide area network. The prototype, based on a distributed architecture, includes capabilities for policy creation and management, dynamic policy negotiation, and dynamic policy provisioning. The policy negotiation facilitates the rapid deployment of a coalition network while the dynamic policy provisioning automates the configuration and management of network services including firewalls, virtual private network connections, routing, quality of service (QoS), and domain name services. Such a PBNM system enhances an organization's ability to react to network incidents identified by a network situational awareness assessment. Although the focus of the current research is a military coalition environment, the system can be used in any distributed enterprise or collaborative environment