Network Node Apparatus System, Apparatus, and Method

Between network node apparatuses that operate as a duplex system, when a failure occurs in an information processing unit of one system, the service is maintained and continued in an information processing unit of the other system without interruption of the service. In a system using an active system network node apparatus 100-1 and a standby system network node apparatus 100-2 both in an operating state, a switch processing unit 110 has a transfer processing unit 112 that copies and transfers a packet flow to be a subject of information processing in the information processing unit 200 to two output destinations, when the switch processing unit operates as an active system. The information processing unit 200 has a mutual monitoring processing unit 203 that checks mutual operating states between the active system and the standby system, determines that a failure has occurred when the active system does not return a response and causes the standby system to operate as an active system, and a halt processing unit that, upon operation as the information processing unit of the standby system, halts output of a packet to be a subject of information processing.