【作者】 赵婧如；

【导师】 姜建国；

【作者基本信息】 西安电子科技大学 ， 计算机应用技术， 2009， 硕士

【摘要】 随着计算机网络技术的飞速发展,各组织机构对计算机网络的高度依赖性使得网络运行的可靠性变得至关重要。从而对网络管理提出了更高的要求。在网络管理中,网络拓扑信息是其它所有管理功能的基础。只有在掌握了被管理网络正确、完整的拓扑结构之后,才能对网络进行正确、有效的管理操作。如何快速、高效并准确地发现网络拓扑信息是当前网络管理领域关注的重要问题。本论文重点研究了网络拓扑发现中的各种算法,完整的网络拓扑发现必须分两个层次来进行：逻辑拓扑发现和物理拓扑发现。本文首先分析了现有的主流逻辑拓扑发现算法,系统、详细地总结了这些算法的优缺点,并针对这些算法的不足提出了逻辑拓扑发现的改进方案,解决了传统算法中存在的诸多问题。其次,本文就物理拓扑发现问题,重点分析了被广泛关注的基于地址转发表的物理拓扑发现算法,并总结了该类算法的局限性。给出了一套基于生成树协议的用于推导物理设备端口间连接关系的定理与规则,并基于这些规则设计了相应的拓扑发现算法。该算法不依赖于地址转发表的完整性,不需要注入附加的流量,能够发现被生成树协议阻塞的连接和不支持SNMP的设备,拓扑发现的准确度高。最后本文基于以上提出的改进算法,设计实现了一个用于拓扑发现的原型系统。并在实际的网络环境中进行了测试,测试所生成的网络拓扑与实际的网络拓扑相符,验证了本文提出的改进算法的正确性和有效性。VLAN技术的广泛应用和IPv6各项技术的逐渐成熟,已向网络拓扑发现提出了新的挑战。含VLAN的物理拓扑发现,及IPv6网络环境下的拓扑发现都是值得进一步研究的重要内容。更多还原

【Abstract】 With the rapid development of network technology, all kinds of organization depend on network so much that the operational reliability of network become vital. Therefore, It sets higher demands for network management. Network topology information is the fundament of all other management function in network management. Only by grasping the accurate and complete topology information can we make the suitable and efficient network management. How to discover network topology information rapidly and efficiently is the focus of attention in network management field.In this paper we focus on all kinds of algorithm of network topology discovery, the result show that we can discover comprehensive network topology by two layers: logical network topology discovery and physical network topology discovery.Firstly, this paper analyzes current mainstream algorithm of logical network topology discovery and summarizes the advantages and disadvantages in detail. We propose several improved methods about those disadvantages and solved some problems of classic algorithm.Secondly, this paper investigates the physical network topology algorithm based on address forwarding table and summarizes the restriction of the algorithm. This paper gives some theorems and rules based on Spanning Tree Protocol which are used to infer the connections between network node’s ports. A physical network topology discovery algoritlim based on those rules was designed.The algorithm does not depend on address forwarding table completion and do not need extra network traffic.It can discovery the blocked connections and non-SNMP equipments. Accuracy of the algorithm is higher.Finally, a prototype system based on these improved algorithms has been designed and implemented in this paper. The prototype system has been tested in actual network environment. The experimental result is in conformity with actual network topology, verifying that our algorithm can efficiently discover the accurate network topology.With the development of VLAN technology and IPv6 technology, network topology discovery is confronted with new challenges. Physical topology discovery in network with VLAN and topology discovery in IPv6 network are worth further researching.更多还原