Patent ID: 7069343

Claim:
A topology discovery method, comprising: (a) contacting each router in a first set of routers, the first set of routers being part of a common autonomous system; (b) for each contacted router in the first set of routers, accessing a first set of managed objects and/or variables defined by a network management protocol, the first set of managed objects and/or variables comprising a listing of interface addresses corresponding to the contacted router, how each interface address is connected to a next hop interface of another router, and an interior gateway routing protocol identifier identifying an interior gateway routing protocol present on each link between an interface of the contacted router and the corresponding next hop interface; (c) for each contacted router in the first set of routers, processing the first set of managed objects and/or variables to identify each next hop interface and, for each next hop interface, how the corresponding interface of the contacted router is connected to the selected next hop interface and an interior gateway routing protocol identifier identifying an interior gateway routing protocol present on each link between the corresponding interface of the contacted router and the selected next hop interface; (d) based on the first set of managed objects and/or variables, determining a second set of routers using a first interior gateway routing protocol, the second set of routers being in the autonomous system; (e) contacting each router in the second set of routers; (f) for each contacted router in the second set of routers, accessing a second set of objects and/or variables defined by the first interior gateway routing protocol, the second set of managed objects and/or variables comprising a listing of interface, link, and/or network addresses corresponding to the members of the second set of routers; and (g) processing the first and second sets of objects and/or variables to provide a network topology model.