毕业论文-基于GRE-over-IPsec-VPN设计与仿真.doc

PAGE\*MERGEFORMATIV摘要人类社会已经进入21世纪，计算机信息网络已深入到世界的各个角落，地域、国家、政府、企业甚至家庭。计算机网络的飞速发展给人来带来了诸多便利，而然其潜在的网络信息安全威胁也弥漫在各个领域。本课题设计与论述的是关于网络安全中常用的一种技术——虚拟专用网（VPN）技术。该技术的主要作用：将不在同一区域的内网之间，通过在互联网中建立一种安全隧道，使得内网数据流安全地穿越互联网，而不被外网用户获悉，从而保证内网之间的数据通信安全地穿越互联网。本课题所探讨的VPN技术则是建立在GREoverIPSec技术之上，并通过合肥百大集团的网络拓扑对其进行设计与仿真。GREoverIPSecVPN技术是通过GRE与IPSec相结合，而形成的一种安全性更好VPN技术，其主要借用IPSec的安全加密和GRE支持多播的优点，从而使得VPN网络更加安全。该项技术的主要工作原理：将一个完整的组播、广播数据包或非IP数据包封装在一个单播数据包（IPSEC）里，以处理如OSPF的组播或RIP的广播数据流，以完成在IPSec隧道里通信实体之间的动态路由学习。关键字：网络安全，VPN，IPSec，GRE，动态路由协议（具体是OSPF协议）AbstractThehumansocietyhasenteredthe21stcentury,andthecomputerinformationnetworkhaspenetratedeverycorneroftheworld,regional,state,government,businessesandevenfamilies.Therapiddevelopmentofcomputernetworkshasbroughtmuchconveniencetopeople,andthenthepotentialsecuritythreatnetworkinformationfilledinthevariousfields.Designanddiscussionofthetopicisaboutakindcommonlyusedinnetworksecuritytechnologies-virtualprivatenetwork(VPN)technology.Themainfunctionofthetechnology:thenetworkisnotwithinthesameregionbetweentheInternetbyestablishingasecuretunnelsothatdataflowswithinthenetworkthroughtheInternetsafelywithouttheuserwasinformedbyexternalnetwork,thusensuringthenetworkbetweensecuredatacommunicationsthroughtheInternet.ThetopicsarediscussedinVPNtechnologyisbuiltontopofGREoverIPSectechnology,andthroughHefeiBaidaGrouptodesigntheirnetworktopologyandsimulation.GREoverIPSecVPNtechnologyisthroughthecombinationofGREandIPSec,andtheformationofabetterVPNsecuritytechnology,itsmainborrowingGREIPSecencryptionandsecurityadvantagesofmulticastsupport,whichmakesthenetworkmoresecureVPN.Themainworkingprincipleofthetechnology:acompletemulticast,broadcastpacketsorIPpacketsareencapsulatedinaunicastpacket(IPSEC)inordertodealwith,suchasOSPForRIPbroadcastmulticastdatastreamstocompletethecommunicationentitiesintheIPSectunnelbetweenthedynamicroutingstudy.Keywords:NetworkSecurity,VPN,IPSec,GRE,DynamicRoutingRrotocols(specifically,theOSPFprotocol)目录摘要IAbstractII第一章网络安全与VPN简介11.1网络安全简介11.2V