Patent ID: 6697338
Filing Date: 2004-02-24
Classification: H04L

Abstract:
A method of discovering a physical topology of a network having a number of network elements each of which is assigned to one of a number of bridged LAN segments, where the bridged LAN segments are organized into a plurality of subnets within the network, wherein each network element has one or more interfaces each of which is physically linked with an interface of another network element, the method comprising:generating address sets comprising address forwarding table information for each interface of each network element, wherein members of a given address set correspond to network elements that can be reached from the interface for which the given address set was generated; comparing the members of first address sets generated for corresponding interfaces of a given network element with members of second address sets generated for corresponding interfaces of network elements other than the given network element, and determining a set of candidate connections between one or more interfaces of the given network element and one or more interfaces of another network element wherein, for each candidate connection, (a) none of the members of a first address set is also a member of a second address set, and (b) the members of the first address set and the members of the second address set collectively represent all network elements assigned to each subnet represented by the members of the first and the second address sets; and if only one candidate connection is determined between a first interface of the given network element and a second interface of another network element, identifying the one candidate connection as an actual connection between the first and the second interface, and eliminating from the set of candidate connections those connections with other network elements which are in the same subnet as the given network element when more than one candidate connection is determined.