Distributed Denial of Service, which depletes the network's resource and denies service to legitimate users, is one of the hardest security problems in the Internet. 分布式拒絕服務(wù)攻擊,目的在于耗盡網(wǎng)絡(luò )資源從而使合法用戶(hù)的服務(wù)請求被拒絕,是最難解決的網(wǎng)絡(luò )安全問(wèn)題之一。