Patent ID: 6490246
Filing Date: 2002-12-03
Classification: H04L

Abstract:
A router back-up method in a system where a plurality of routers are mutually connected via a network, comprising:passing a routing protocol process from a router in an active mode to a router in a standby mode when a failure occurs in said router in said active mode, wherein said router in said active mode and said router in said standby mode are each provided with the same router identification (ID) in advance, wherein each router comprises: a route calculation unit which performs a routing protocol process to create a routing table for deciding a packet route, and sends a packet in the network according to said routing table, wherein said route calculation unit of said router in said active mode performs said routing protocol process, holds routing protocol information including network link-state information containing identifying information of the router, neighboring router state information, and interface state information of said network to which said router is connected, and sends said network link-state information containing said identifying information of the router to said route calculation unit of said router in said standby mode, wherein said route calculation unit of said router in said standby mode receives and holds said network link-state information containing said identifying information of the router sent from said router in said active mode, monitors said router in said active mode, and when said router in said standby mode is shifted from said standby mode to said active mode due to a failure that occurred in said router in said active mode, said router shifted from said standby mode to said active mode takes over said routing protocol process as a router specified by said identifying information of the router in which the failure has occurred and which sent said network link-state information containing said identifying information, wherein said router shifted from said standby mode to said active mode performs said routing protocol process according to said network link-state information containing said identifying information of the router held in said router shifted from said standby mode to said active mode.