基于地址转发表的交换式以太网拓扑发现方法

提出一种称为连接推理技术(connections reasoning technique)的谓词逻辑推理方法推导节点间的连接关系.该方法把交换机地址转发表翻译为一组谓词公式,把拓扑发现问题转变为一个谓词逻辑推理的数学问题,借助数学工具对拓扑发现问题进行研究.基于连接推理技术提出了一种拓扑发现算法,与现有方法相比:(1)该方法能够更充分地利用不完整地址转发表的冗余信息,只需一小部分转发表就可以把整个网络拓扑构建出来;(2)该方法完全适用于多子网交换域的拓扑发现.此外,还提出了一种开销很小的动态网络拓扑发现方法.该算法成功地应用在社区宽带综合业务网络管理系统中.

A Method of Topology Discovery for Switched Ethernet Based on Address Forwarding Tables

In this paper, the connections reasoning technique (CRT) based on the predication logic is proposed to infer the connections between network nodes. This technique interprets the address forwarding tables (AFTs) as a set of predicate formulas and translates the topology discovery into a mathematic problem of logic reasoning, so that the topology discovery can be studied by resorting to mathematic tools. An algorithm for topology discovery based on CRT is proposed in this paper. Compared with current discovery algorithms, this method excels in: 1) Applying the redundancies in AFTs more effectively, so that the whole topology can be built up by just small part of AFTs; 2) Naturally resolving the problem of topology discovery for multi-subnet switched domain without any extensions. Furthermore, a method with little cost is proposed to discover the dynamic topology in this paper. This algorithm is successfully applied to the network management system for CBISN (Community Broadband Integrated Services Network).