介绍了路由重分发的工作原理和技术要点,并利用GNS3模拟器,设计实现了路由重分发的仿真实验,同时探讨了路由重分发可能产生的问题及相应的解决方法。实践表明,使用GNS3模拟有助于培养学生的创造力,提升学生的网络设计、配置和验证等综合能力。

The paper introduces the principles and technical key points of the routing redistribution technology, of which the simulated experiments are designed by using GNS3 simulator. Moreover, some relative problems and solutions caused by routing redistribution are discussed in this paper. Practices show that GNS3 simulator can help students to develop their creativity, improve the comprehensive ability of network design, conifguration and authentication, etc.

利用虚拟机VMware与GNS3网络设备互联技术，在单机环境中搭建了一个典型网络架构的攻防实战演练平台。结合Ubuntu下的Yersinia攻击工具，实例给出了对Windows 2003 Server下的DHCP服务器和热备份路由（HSRP）汇聚交换机的具体攻击过程和相应的防御措施，验证了VMware和GNS3构建虚拟网络实验平台的可行性，为学习和研究网络攻防技术提供了一条实战演练的有效途径。

Making use of virtual machine VMware connected to GNS3 network equipment ,this paper proposes a network attack and defense combat exercise platform of typical network architecture in the single computer environment .Combined with the attack tools of Yersinia in Ubuntu ,experimental case puts forward detailed attack process and corresponding defense measures for DHCP Server of the Windows 2003 Server operation system and hot standby routing protocol (HSRP) aggregated switch ,verifies the feasibility of VMware and GNS3 to construct a virtual network experiment platform ,and provides an effective way to combat exercises for learning and research of network attack and defense technology .

采用乳液共混、机械共混及两者并用制备了石墨烯（ GNs ）/天然橡胶（ NR ）复合材料,采用扫描电镜（ SEM）、X-射线衍射（ XRD）仪、高阻仪、动态热机械分析（ DMA）仪、万能拉力试验机、热重分析（ TG）仪对材料微观结构与宏观性能的相关性进行研究。研究表明：相比于机械共混,乳液共混有助于GNs的均匀分散和导电网络的形成,GNs/NR复合材料表现出较优的机械和导电性能,定伸应力和导电率分别是机械共混法的3倍和100倍；乳液共混后的机械共混则破坏了原有的导电网络,复合材料导电率下降；随后的机械共混打乱了原有的网络结构,并促使了GNs片层的卷曲化,降低了GNs与NR的接触面积,复合材料的综合性能下降。

Graphene/natural rubber composites were fabricated by three methods, i. e. two-roll milling, self-assembly based latex compounding,and combined the two. The relations between fabrication,morphology and property were investigated by SEM,XRD, DMA etc. It is found that property improvements are strongly dependent upon the processing and morphology. Compared with me-chanical milling that is inefficient to exfoliate the graphene,self-assembly based latex compounding afforded better dispersion and a web-like morphology consisting of graphene networks between the latex particles,thus showing the best mechanical(3 times)and e-lectrical property(100 times). However,subsequent mechanical mill processing broke down the established network,as well as in-duced the curling of GNs,thus yielding a depressed interfacial contact between matrix and fillers,and inferior property at last.

SSL VPN技术利用SSL协议提供的基于证书的身份认证、数据加密和消息完整性验证机制，为用户远程访问公司内部网络提供了安全保证。基于SSL VPN系统的基本构架，使用GNS3模拟器仿真SSL VPN系统，在远程用户和内部网络之间构建基于SSL的VPN，实验结果表明SSL VPN在点对网互连方面有较好的易用性和安全性。

SSL VPN technology provides security assurance for remote users accessing to the internal network by certificate authentication,data encryption and message integrity verification mechanism. The SSL VPN system is built between remote us?ers and the internal network by use of GNS3 simulator based on the basic framework of the SSL VPN system. The experimental results show that SSL VPN is more usable and safer for the interconnection between points and network.

分析了大型网络架构下的多个不同的网络协议之间的路由重分布所引起的潜在环路问题,借助网络设备仿真软件GNS3,并以实验的形式证明在OSPF协议与RIP协议之间重发布过程中引起的潜在环路问题。文章对RIP汇总引起的重发布的潜在环路又进行了实验模拟与分析。最后,通过实验,表明文章所使用的解决多协议之间重发布的潜在环路的方法的可行性。

This article analyzes the potential loop which happens in the process of multipoint bidirectional redistribution between different routing protocols in a large-scale network architecture.With the network device emulation software GNS3,there will be the potential loop during the process of the redistribution between the protocol of RIP,OSPF by the form of experiment.Some Experimental simulations was introduced to Elaborate the potential loop of distribution caused by RIP summary.It shows that it’s possible to use this method to solve the potential loop during the distribution among multitude of route protocols through experiments.