Network, node device, network redundancy method and recording medium

摘要

There is provided a network capable of coping with occurrence of failure including a plurality of autonomous networks. The network includes an existing network A including a plurality of autonomous networks AS1 to AS6 in which the same routing protocol is employed and an additional network B added to the existing network to provide redundancy to the network. The additional network B is an autonomous network ASP dedicated to backup routes and is less in size than the existing network A. Traffic on the existing network A is transmitted by use of the additional network B.