COMMUNICATION SYSTEM, IPsec TUNNEL TERMINATION DEVICE, AND IPsec TUNNEL COMMUNICATION CONTINUATION METHOD USED FOR THEM

摘要

A control unit of a connection destination device assigns a connection destination device address to a virtual line unit. In response to an instruction from the control unit, the virtual line unit sets a line as an active line to be used for communication and, to make it appear to an external device that the connection destination device address is assigned to the line, notifies a preceding-stage device that the line has the connection destination device address. Thereafter, the line is used to establish, communicate, or disconnect an IPsec tunnel from a connection source device to the connection destination device.