Information processing system with communication system and hot stand-by

Abstract

A running information processing system and a standby information processing system are connected via networks to a bridge to communicate with partner terminals. A hot standby function is provided such that the partner terminal is not required to include a path change-over function. When it is assumed via an alive or dead state monitoring path that the running system is not operating normally, the standby system takes over processing of the running system, adds to a frame a communication address of the running system as the communication address of the transmission source, and sends the frame via the bridge. The bridge includes a plurality of ports to connect a plurality of LANs, and transfers between the ports the frame to which the communication addresses of the transmission source and destination of the information processing system are added for a relaying operation of the frame. The relaying operation is accomplished according to a latest correspondence relationship between the port having received the frame sent from the information processing system of the transmission source of the frame and the communication address of the information processing system of the transmission source added to the frame. When the standby system transmits via the bridge a frame including the communication address of the running system as the communication address of the transmission source, the bridge transmits the frame destined to the running system to the standby system without recognizing change-over of the running system.