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  1. 1. 互联网之父:还有 80%没有接入互联网 如果我们不采取行动,到 2010 年,我们将用尽所有的 IP 地址。Google 的首席互联网传道官,常被称作”互联网之父“的温顿瑟夫,上月接受读写网采访 时如是说(后面有采访视频) 随着互联网接入设备尤其是手机的猛增,空置 IP 越来越少,而且目前也只有 20%接入了互联网,这是个问题。对于消费者,如果你认为这不会妨碍你, 再好好想想。最近购买的小玩意,支持不支持 IPv6. TCP/IP:是怎么一回事 为了深入理解 IPv6 我们需要简单介绍一下 TCP/IP 而这意味着我们要时光倒流去追溯一下历史。 这一切始于 1969 年,当高级研究计划署网络(ARPANET)通过网络传送文件时采用网络控制协议(NCP)。这一协议,如果你从它的字面意思理解, 就是网络和计算机可以和其他的网络和计算机对话。 由于昂贵,笨重,速度慢,NCP 在 1973 年开始受到限制,美国国防高级研究计划署 (DARPA)启动了一个新项目, Internetting project 力图开发一个更好的 对话协议。 这项研究奠定了互联网的基石,协议的开发也成为我们现在熟知的 TCP/IP 协议系列。 在它的基本层面,IP 部分保证了数据包投递到正确的位置,因此为网络上所有的主机都提供了独一无二的号码(IP 地址)作为标识,TCP 部分管理数据 传输。 1983 年一月一日 NCP 成为历史,这一天 ARPANET 转移到了新的 TCP/IP 协议,因此这也被认为是互联网正式诞生。 从 V1 到 V6 Vint Cerf 和 Robert Kahn 设计 TCP/IP 了之后,随着互联网的发展,DARPA 与 3 方(BBN,斯坦福和伦敦大学学院)签署协议继续开发新的操作版本, 四个更好的 TCP/IP 版本被开发出来,TCPv1, TCPv2, 然后进入 TCPv3 and IPv3。稳定运行直至 TCPv4 和 IPv4;我们现在使用的标准协议。 IPv4 使用 32 位地址,理论上最多可提供 4,294,967,296 (232)个地址。但是由于一些还需要留有特殊用途,实际上还达不到这个数量。 IPv6 采用 128 位地址,可以提供 3.4e+38 (大约比 340 兆, 兆 ,兆还多些)个地址。此外它还改进了 IPv4 使用上的一些问题,比如数据安全。 IPv6 预计将缓慢替代 IPv4,这两种协议系统将共存很多年。 但是,IPv5 出了什么问题? 在我们讲 IPv4 和 IPv6 时,自然而言很多人就会问,怎么没有 IPv5 呢。IPv5 是一个试验性的音频/视频流协议。来自克里科里安的信息命名为 ST 的互联 网流协议在上世纪 70 年代诞生,20 年后升级为 ST2,它通过 IBM,NeXT, Apple 和 Sun 的商业化项目开发出很多应用。ST he ST2 不可思议的命名 为“5”。实际上它和 IP 地址基本结构没有什么关系,因此 IPv5 通常被不被重视。 IP 地址已不满足我们的需要 虽然单一网络协议的建立是为网际网络世界确立秩序的重要一步,但是没有人可以预料到互联网的发展以及日益增长的对 IP 地址的需求。 Cerf 最近补充道,我唯一保守的就是在 1977 年做的决定,那个时候还不知道互联网能不能工作,128 位地址在那个时候看起来没有必要。 看看下面 Cerf 谈论 IPv6 的视频-了解为什么转到 IPv6 是如此重要。
  2. 2. Vint Cerf: We Still Have 80 Per Cent of the World to Connect "By 2010 we will have run out of IP addresses if we don't do something about it," Vint Cerf, Google's chief Internet evangelist and the man commonly referred to as "the father of the Internet," told ReadWriteWeb last month. (Video embedded below.) With the number of Internet-enabled devices particularly mobile phones soaring, very few IP addresses remain vacant, and with only about 20 per cent of the world connected to the Net, that's a problem. And consumers, if you think this doesn't affect you, think again. That latest gadget you bought - is it IPv6 compatible? TCP/IP: So, what's it all about anyway? To fully understand IPv6 we need to take a look at TCP/IP and this means a quick trip back in time. It all started way back in 1969, when the Advanced Research Projects Agency Network (ARPANET) was using a transmission protocol known as the Network Control Protocol(NCP) to transmit data across networks. Protocols, if you think of them as languages, are needed so that networks and computers can talk to one another. Expensive, cumbersome and slow, NCP was found to be limiting and in 1973, the U.S. Defense Advanced Research Projects Agency (DARPA) initiated a research program, known as the Internetting project, to develop a better communication protocol. The networks which emerged from this research became the basis for what we know as the Internet, and the protocols developed during this time became known as the TCP/IP Protocol Suite. At its most basic level, the IP part ensured packets were routed to the right place by providing unique identifying numbers to all hosts connecting to the network, and the TCP part managed the transfer of that data. On January 1, 1983 NCP was deemed obsolete when the ARPANET switched over to the new TCP/IP protocol suite, and as a result, marked this date as the official birth date [for some] of the Internet. Getting to V1 from V6 According to the Living Internet, after Vint Cerf and Robert Kahn designed TCP/IP, DARPA contracted with three sites to develop operational versions: BBN, Stanford and the University College London, and four increasingly better versions of TCP/IP were developed: TCPv1, TCPv2, which then split into TCPv3 and IPv3. Stability finally arrived with TCPv4 and IPv4; the standard protocol we know and use today. IPv4 uses 32-bit addresses, which limits the address space to 4,294,967,296 (232) possible unique addresses. But, as some of these are reserved for specific purposes, it reduces the total number available. IPv6 with its 128 bit addresses increases the number of potential unique addresses to 3.4e+38 (a little bit more than 340 trillion, trillion, trillion). Additionally, it is designed to rectify issues found with IPv4 such as data security. IPv6 is expected to slowly replace IPv4, with the two protocol systems expected to run simultaneously for many years. But, what happened to IPv5? Typically, the most often asked question when talking about IPv4 and IPv6 is what happened to IPv5? IPv5 was known as an experimental streaming audio/video protocol. According to Raffi Krikorian, a protocol named ST, the Internet Stream Protocol was created in the late 1970's and two decades later revised to become ST2, at which point it was implemented in commercial projects by IBM, NeXT, Apple and Sun. ST and ST2 were already
  3. 3. given that magical "5" notes Krikorian. Given it had little to do with the fundamental structure of IP addressing, IPv5 is not commonly recognized. We're running out of IP addresses While the establishment of a single networking protocol was an important step toward maintaining order in the then new internetworked world, no one could have guessed the growth of the Internet, nor the number of IP addresses required to cover the ever growing demand. "My only defense is that decision was made in 1977, at a time when it was uncertain if the Internet would work," Cerf said recently, adding that a "128-bit address space seemed excessive back then." Watch our video below to get Cerf's take on IPv6 - and why switching over is so important.