NAT技术及IPv4到IPv6地址转换研究

IPv6是一种新型的互联网协议，用来克服现有标准IPv4在可扩展性和服务方面的不足。介绍了NAT技术，探讨了IPv4/IPv6过渡中的地址转换机制，同时也指出NAT技术在IPv4向IPv6过渡中的一些不足。     

Building Traversing NAT IPv6 Tunnel Gateway System Relies on Netfilter/Iptable Framework

The transition from IPv4 to IPv6 is doomed to be a long process. The network Address translation （NAT） technology is used very popularly in IPv4 network to make up the shortage of network address. It is a desiderated problem to make the users behind NAT gateway to access to IPv6 networks. By studying the transition technology from IPv4 to IPv6 and introducing NAT technology in IPv6, a scenario is put forward through 6to4 tunnel The scenario is implemented and the gateway system＇s performance is analyzed.     

城域网IPv4到IPv6过渡方案的分析研究

全球IPv4地址已经耗尽,IPv6的需求不断扩大,但是IPv4到IPv6过渡是一个逐步演进的过程,如何使用各种过渡技术在现有IPv4网络设备资源下进行IPv4网络到IPv6网络的平滑过渡已成为当代互联网发展的方向。因此提出了城域网宽带拨号用户IPv4到IPv6过渡方案,即以双协议栈为基础技术,同时采用6to4/ISATAP Tunnel。并且在此环境下运行WWW、FTP、Http、DNS等网络应用平台。     

NAT444部署关键问题探析

随着IANA宣布IPv4地址分配完毕,IPv4向IPv6过渡已成为必然趋势,NAT444是一种向IPv6平滑过渡的模型。文章在介绍NAT444部署模式的基础上,分析探讨NAT444部署相关的CGN设备部署、用户溯源方式、AAA系统改造、用户终端过渡方面的关键问题,最后提出了NAT444发展的建议。     

简述IPv4向IPv6过渡阶段的安全性问题

阐述了IPv4向IPv6过渡的必要性，分析了IPv4与IPv6的主要差异。探讨了IPv4向IPv6过渡阶段的安全性问题以及IPv6安全机制的应用。重点分析了IPv6提供的两种安全机制，以便这两种机制能为IPv4向IPv6过渡阶段的安全性提供更好的支持和保障。     

IPv4／IPv6混合网络中的SIP通信解决方案

IPv6是IP协议的新版本,它最终会取代IPv4成为未来互联网的核心网络协议,然而,过渡时会有一段IPv4与IPv6共存时期。由IETF定义,SIP已成为多媒体通信的最重要技术之一。文中在分析SIP机制和常见的IPv4向IPv6过渡技术的基础上,提出了一种双协议栈与TURN相结合的解决方案。     

NAT444在广西联通城域网内部署的探讨

运营商面临IPv4地址资源已经枯竭,而IPv6网络架设和运营需要很长时间才能够实现,因此利用NAT444技术缓解IPv4地址资源匮乏的窘境成为运营商的主要手段.分析了广西联通典型城域网的特点,就NAT444在现有网络部署时可能引入的业务回溯处理、部署方式、地址与业务和运行维护等相关问题进行探讨.     

ITU-TNGN和IPv6标准化、产业发展和可能的过渡方式

随着新业务和应用的出现,NGN和IPv6技术的发展和应用日益成为业界关注的焦点。本文对ITU-T NGN和IPv6的技术现状、标准化和产业化发展情况作了一个简单的介绍。文章还阐述了由IPv4网络向IPv6网络过渡的三种方式和运营商的可能选择。最后,文章对中国的以IPv6为基础的下一代互联网的发展进行了展望。     

基于NAT444的IPv6过渡方案研究

在IPv4公有地址即将耗尽的背景下,互联网从IPv4向IPv6演进已刻不容缓。本文对基于NAT444的IPv6过渡方案进行了研究和探讨。对NAT444的技术原理进行介绍,结合目前电信运营商IP城域网的现状提出了基于NAT444技术的部署方案,包括部署方式、冗余保护、端口分配、地址分配、接入流程及其他相关支撑系统配合改造等。     

Evolutionary gaming approach for decision making of Tier‐3 Internet service provider networks migration to SoDIP6 networks

With the increasing number of Internet of Things (IoT) devices, current networking world is suffering in terms of management and operations with lack of IPv4 addresses leading to issues like network address translation (NAT) proliferation, security and quality of services. Software‐defined networking (SDN) and Internet Protocol version 6 (IPv6) are the new networking paradigms evolved to address related issues of legacy IPv4 networking. To adapt with global competitive environment and avoid all existing issues in legacy networking system, network service providers have to migrate their networks into IPv6 and SDN‐enabled networks. But immediate transformations of existing network are not viable due to several factors like higher cost of migration, lack of technical human resources, lack of standards and protocols during transitions, and many more. In this paper, we present the migration analysis for proper decision making of network transition in terms of customer demand, traffic engineering, and organizational strength with operation expenditure for network migration using evolutionary gaming approach. Joint migration to SDN‐enabled IPv6 network from game theoretic perspective is modeled and is validated using numerical results obtained from simulations. Our empirical analysis shows the evolutionary process of network migration while different internal and external factors in the organization affect the overall migration. Evolutionary game in migration planning is supportive in decision making for service providers to develop suitable strategy for their network migration. The proposed approach for migration decision making is mostly applicable to fairly sustained service providers who lack economics, regulation/policy, and resources strengths.     

移动IPv6实施的关键问题及在CDMA网络中的应用

IPv4的NAT缺陷、缺乏固定地址限制了CDMA网络中移动IP业务的发展,CDMA移动网络向IPv6承载过渡是必然趋势。本文探讨了移动IPv6在CDMA网络中的应用,着重分析了CDMA网络中应用移动IPv6所面临的服务质量、安全、认证、DNS自动发现、演进等问题,并对现有CDMA网络实体的改动加以阐述。     

IPv6隧道技术研究与应用

隧道技术是IPv4网络向IPv6网络过渡初期最重要的技术。根据个人用户上网的方式分为NAT上网用户与非NAT上网用户并分析不同类型的用户如何登陆到IPv6网络,对于非NAT上网用户可以采用访问IPv6网络,对于NAT上网用户Teredo隧道和隧道代理访问IPv6网络,最后演示IPv4用户如何登陆IPv6网络。     

IPv6的安全机制及其对现有网络安全体系的影响

IPv6不但解决了当今IP地址匮乏的问题,并且由于它引入了加密和认证机制,实现了基于网络层的身份认证,确保了数据包的完整性和机密性,因此,可以说IPv6实现了网络层安全。但是,这种安全不是绝对的。并且由于IPv6的安全机制,给当前的网络安全体系带来了新的挑战,致使许多在现有的网络中对保护网络安全中起着重要作用的工具受到巨大的冲击,急需安全专家进一步研究和积累经验,尽快找出合适的解决方法。     

从IPv4向IPv6的过渡

目前,IPv6及相关协议已经相对成熟.然而,IPv4网络向IPv6网络的过渡和互通仍然是个艰巨的任务,直接影响了IPv6的发展.本文在对现有的各种互通与过渡方案进行综合分析的基础上,针对目前转换与互通中所存在的问题,提出了一种穿透NAT实现IPv6终端互连的隧道机制.该机制可以支持所有常见的NAT类型,无需特殊的IPv6地址前缀,可以向用户提供固定的IPv6地址.另外,针对IPv6网络和IPv4网络间的信息交互的不断增加,而基于通用处理器的IPv4/IPv6转换网关很难满足性能需求的现状,基于专用网络处理器平台研发了高性能的IPv4/IPv6转换网关,在IPv4与IPv6网络间实现了高性能的地址和协议转换,为IPv4网络向IPv6网络的平滑升级提供了保证.     

基于隧道技术的IPv6迁移策略

介绍IPv4向IPv6平滑迁移的几种方案及实现的工作原理,着重探讨隧道技术中存在的若干问题.     

城域IP骨干网的演进方案

运营商IP城域网正不断突破带宽限制以满足新业务形态的需求,为了给用户提供差异化的用户服务体验,运营商发现自己需要一个更加智能的承载网,提供丰富而强大的2、3层业务能力.同时在IPv4地址快速消耗的背景下,如果向IPv6迁移构建一个可管可信可控的新型网络也是运营商面临的新挑战.本文系统的分析探讨运营商建设新一代IP数据网面临的挑战及可能的应对策略.     

一种高性能IPv6/IPv4安全网关

在IPv4/IPv6并存过渡时期提供强有力的网络安全保障,是实现面向NGI(next generation Internet)平滑演进和发展的关键。在NAT-PT协议转换和流量负载均衡等技术分析的基础之上,提出了一种具备IPv4/IPv6异构网络边界访问控制功能的高性能安全网关模型NAPTSG,详细论述了其系统设计思路,并且给出了其原型的实现及测试情况。     

一种SCTP报文的NAT穿越方法

流控制传输协议（SCTP）即将成为下一代网络中的传输层协议,在未来互联网和移动网络中发挥重要作用,然而目前网际协议（IP）网络中大多数网络地址转换（NAT）设备对SCTP报文转发缺乏兼容性支持。分析并解决了SCTP在当前IPv4网络实施中所遇到的NAT阻断问题。利用在收发端协议栈上进行功能扩展,提出了一种新的SCTP报文的NAT穿越方法,在不修改当前网络NAT设备的前提下完成NAT穿越,并在原型机上测试验证了解决方案的可行性和有效性。     

A Novel Load Balancer for Scalable Multi-NAT

Due to the upcoming IPv4 address exhaus- tion, the transition from IPv4 to IPv6 becomes an urgent problem restricting the growth of Internet. Multi-NAT, which is desired in large scale IPv4-IPv6 coexistent net- work, has inherent difficulties in the stateful traffic bal- ancing and failure recovery. The existing schemes cannot handle them due to the absence of state synchronization. In this paper we propose a novel Load balancer （LB） to build a Scalable multi-NAT （SMNAT） in large scale net- work for various IPv4-IPv6 coexistent scenarios. The LB is specifically designed to have a translation pattern re- lated hash keys and load-balance bi-directional traffic in two modes. Additionally an Adaptive reassigning algo- rithm （ARA） running in LB is presented to schedule flows adaptively to reduce the cost of state synchronization as well as guarantee the performance in load balancing. Com- paring SMNAT with the existing load balancing schemes, the simulation result shows that our SMNAT outperforms other schemes and meets the goals of large scale NAT.     

Endpoint-agnostic address hopping communication — a network-based design by fully exploiting IPv6 huge space superiority

Network address hopping (NAH) proposed a mechanism to enhance data protection in communications across untrusted networks. It spread the data stream of a communication session across multiple channels, which tried to obstruct information interception in the first place by obscuring the fact that communication takes place between certain end-points. However, the time-stamped packets between two peers would provide a hint for correlating the intercepted packets in case the encryption of the counter got compromised. Furthermore, due to synchronization, the Internet Protocol version 6 (IPv6) addresses pair of the channel ends would appear and disappear strictly, which would perform time-relevance character. A Network-based hopping communication mechanism (NetHop) is proposed in this paper. The address hopping function is deployed on the network side instead of endpoint, which can support secure hopping communication function for universal endpoints without any restriction of Operating System or hardware. By using IPv6 to IPv6 network address translation (NAT), NetHop fully exploits the superiority of IPv6 huge address space. The hopping addresses are generated by hash function and the hopping addresses pair can be chosen randomly. Consequently, NetHop performs better on randomness and concealment than channel-rule NAH.