交换式以太网物理拓扑结构的自动发现

准确及时的拓扑结构信息是网络性能监测与评估、故障发现与定位、资源分配与管理等一系列维护工作的基础.交换式以太网是目前局域网的主要组网方式，其拓扑结构被看做为一棵拓扑树，并把网络节点之间的连接关系分为直系关系和旁系关系，给出一组判定定理用以确定网络节点之间的连接关系.基于上述定理，提出了一个新的拓扑发现算法，该算法能够利用不完整的地址转发表构造出整个网络拓扑结构.该算法已成功地应用于社区宽带综合业务网络管理系统(CBISNMS)中.

Automatic Discovery of Physical Topology in Switched Ethernets

Accurate and up-to-date knowledge of topology serves as the basis of a number of network management functions, such as performance monitoring and evaluation, fault detection and location, resource allocation and etc. In this paper, the topology of a switched Ethernet, the most prevalent kind of connection layouts of LANs, is abstracted to a tree and the connection relationships between the network nodes are determined as lineal connections and collateral connections. A set of theorems to determine the nodes' relationships is also presented. Based on the above theorems, a new algorithm for physical topology discovery is proposed, which can construct the whole topology utilizing the incomplete AFTs (address forwarding tables). As an important part of a community broadband integrated services network management system (CBISNMS), this mechanism is working successfully.