COMPUTER SYSTEM, CONTROLLER, AND NETWORK MONITORING METHOD

摘要

The objective of the present invention is to improve the strength of security against unauthorized access or interception which uses a spoofed address. The computer system according to the present invention is provided with: a controller; switches which, with respect to received packets complying with a flow entry set by the controller, perform forwarding operations which have been defined at the flow entry; and host terminals connected to the switches. The switches notify the controller of transmission source address information of received packets which do not comply with flow entries that have been set for the switches. The controller assesses that the transmission source address of a received packet has been spoofed if valid address information of the host terminal and the transmission source address information do not match.