隨著網(wǎng)絡(luò)的普及，拒絕服務(wù)攻擊，特別是近年來出現(xiàn)的分布式拒絕服務(wù)攻擊所造成的
危害越來越大。由于它的突發(fā)性、隱蔽性和不確定性，目前還沒有一種有效的辦法來防御這種攻擊。本文介紹了DoS/DDoS 攻擊類型、原理及目前常用的防御辦法，提出了一種新的防御系統(tǒng)。在本系統(tǒng)中，以包過慮防火墻為基礎(chǔ)，增加了一個檢測控制模塊。當(dāng)遭受攻擊時，防御系統(tǒng)根據(jù)一個合法用戶列表自動設(shè)置包過濾規(guī)則，只對合法用戶進(jìn)行轉(zhuǎn)發(fā)，陌生用戶則由檢測控制模塊來檢測其合法性，并代替服務(wù)器進(jìn)行三次握手的連接，從而保護(hù)服務(wù)免受攻擊。
關(guān)鍵詞：拒絕服務(wù) ；防火墻；包過濾；用戶檢測

Design and Implementation of Packet filter firewall-based Dos/DDos Protect System Sun,jianghong Wu,shaohua Zhou,anmin Sun,lipeng (Information Security Institute of Sichuan University ,Chengdu 610064)? 【Abstract】With the development of network,DoS attack ,especially the DDoS attack which expose in recently years,become more and more dangerous.This paper introduces the principle of Dos and DDoS,and the defence method ,then propose a new defends system.In this system,use a detect module to detect the validity of user.When the attack happens,the fire wall will set filter rule,forward the correct data of user,to avoid the attack to the server.
【Key words】DDos; Firewall; Packet Filter; User detection