Due to their characteristics of dynamic topology, wireless channels and limited resources, mobile ad hoc networks are particularly vulnerable to a denial of service （DoS） attacks launched by intruders. The effects o...Due to their characteristics of dynamic topology, wireless channels and limited resources, mobile ad hoc networks are particularly vulnerable to a denial of service （DoS） attacks launched by intruders. The effects of flooding attacks in network simulation 2 （NS2） and measured performance parameters are investigated, including packet loss ratio, average delay, throughput and average number of hops under different numbers of attack nodes, flooding frequency, network bandwidth and network size. Simulation results show that with the increase of the flooding frequency and the number of attack nodes, network performance sharply drops. But when the frequency of flooding attacks or the number of attack nodes is greater than a certain value, performance degradation tends to a stable value.展开更多
Mobile ad hoc networks are particularly vulnerable to denial of service （DOS） attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. T...Mobile ad hoc networks are particularly vulnerable to denial of service （DOS） attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. The new DOS attack, called AA hoc Flooding Attack（AHFA）, is that intruder broadcasts mass Route Request packets to exhaust the communication bandwidth and node resource so that the valid communication can not be kept. After analyzed AM hoc Flooding Attack, we develop Flooding Attack Prevention （FAP）, a genetic defense against the AM hoc Flooding Attack. When the intruder broadcasts exceeding packets of Route Request, the immediate neighbors of the intruder record the rate of Route Request. Once the threshold is exceeded, nodes deny any future request packets from the intruder. The results of our implementation show FAP can prevent the AM hoe Flooding attack efficiently.展开更多
域名系统(domain name system, DNS)协议的性能和操作特性引起了研究和网络运营界的极大兴趣.在这项工作中,通过测量分析来自一个大型DNS服务商的递归服务器数据,从一个大型DNS运营商递归服务的角度考察了用户访问模式及解析状况.面向...域名系统(domain name system, DNS)协议的性能和操作特性引起了研究和网络运营界的极大兴趣.在这项工作中,通过测量分析来自一个大型DNS服务商的递归服务器数据,从一个大型DNS运营商递归服务的角度考察了用户访问模式及解析状况.面向海量的DNS数据,首先提供一种多机分布式并行测量机制和大数据平台存储监控方案,实现了对DNS海量数据的高效测量分析.然后,从用户请求响应率、请求域名的情况、请求用户的情况和域名解析的情况多个维度系统分析了DNS数据的特征,并呈现了多个有价值的测量结果,对提升DNS的运维和洞察DNS的特性具有重要价值.最后,基于对DNS缓存命中率的测量分析,提出一种适用于DNS大型运营商进行在线异常检测的通用框架,并初步验证了框架方案的正确性和可行性.展开更多
基金supported by the National Natural Science Foundation of China (60932003)the National High Technology Research and Development Program of China (863 Program)(2007AA01Z452+2 种基金 2009AA01Z118)Shanghai Municipal Natural Science Foundation (09ZR1414900)The National Undergraduate Innovative Test Program(091024812)
文摘Due to their characteristics of dynamic topology, wireless channels and limited resources, mobile ad hoc networks are particularly vulnerable to a denial of service （DoS） attacks launched by intruders. The effects of flooding attacks in network simulation 2 （NS2） and measured performance parameters are investigated, including packet loss ratio, average delay, throughput and average number of hops under different numbers of attack nodes, flooding frequency, network bandwidth and network size. Simulation results show that with the increase of the flooding frequency and the number of attack nodes, network performance sharply drops. But when the frequency of flooding attacks or the number of attack nodes is greater than a certain value, performance degradation tends to a stable value.
基金This project was supported by the National"863"High Technology Development Programof China (2003AA148010) Key Technologies R&D Programof China (2002DA103A03 -07)
文摘Mobile ad hoc networks are particularly vulnerable to denial of service （DOS） attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. The new DOS attack, called AA hoc Flooding Attack（AHFA）, is that intruder broadcasts mass Route Request packets to exhaust the communication bandwidth and node resource so that the valid communication can not be kept. After analyzed AM hoc Flooding Attack, we develop Flooding Attack Prevention （FAP）, a genetic defense against the AM hoc Flooding Attack. When the intruder broadcasts exceeding packets of Route Request, the immediate neighbors of the intruder record the rate of Route Request. Once the threshold is exceeded, nodes deny any future request packets from the intruder. The results of our implementation show FAP can prevent the AM hoe Flooding attack efficiently.
文摘域名系统(domain name system, DNS)协议的性能和操作特性引起了研究和网络运营界的极大兴趣.在这项工作中,通过测量分析来自一个大型DNS服务商的递归服务器数据,从一个大型DNS运营商递归服务的角度考察了用户访问模式及解析状况.面向海量的DNS数据,首先提供一种多机分布式并行测量机制和大数据平台存储监控方案,实现了对DNS海量数据的高效测量分析.然后,从用户请求响应率、请求域名的情况、请求用户的情况和域名解析的情况多个维度系统分析了DNS数据的特征,并呈现了多个有价值的测量结果,对提升DNS的运维和洞察DNS的特性具有重要价值.最后,基于对DNS缓存命中率的测量分析,提出一种适用于DNS大型运营商进行在线异常检测的通用框架,并初步验证了框架方案的正确性和可行性.
