Patent ID: 7188366
Filing Date: 2007-03-06
Classification: H04L

Abstract:
1. A communication device for defending against a distributed denial of service attack, comprising: a traffic monitoring function section that monitors communication packets passing through the communication device and detects distributed denial of service attacks; a protection module that destroys the distributed denial of service attack packets when the distributed denial of service attacks are detected; an attack source retrieval module that retrieves addresses of communication devices that are close to attack sources at the upstream; a module transmitting section that transmits the attack source retrieval module to a communication device in a defense position at the upstream; and an attack source determining function section that extracts the address of a communication device to be chosen as an upstream defense position from the candidates of upstream communication device close to the attack sources retrieved by the attack source retrieval module, wherein the module transmitting section transmits the protection module to the communication device at the upstream defense position extracted by the attack source determining function section, and also transmits to the upstream communication device the attack packet information related to communication packets detected to be distributed denial of service attacks by the traffic monitoring function section together with the attack source retrieval module, and a traffic examining function section is included in the attack source retrieval module that makes a comparison between communication packets passing through the communication device and the attack packet information received from the module transmitting section and, if it is detected that communication packets that correspond to the attack packet information are passing through the communication device, makes known the fact that the communication device itself is a candidate for the defense position communication device to the transmission source communication device.