Description: 论坛上经常有对P2P原理的讨论，但是讨论归讨论，很少有实质的东西产生（源代码）。呵呵，在这里我就用自己实现的一个源代码来说明UDP穿越NAT的原理。 首先先介绍一些基本概念： NAT(Network Address Translators)，网络地址转换：网络地址转换是在IP地址日益缺乏的情况下产生的，它的主要目的就是为了能够地址重用。NAT分为两大类，基本的NAT和NAPT(Network Address/Port Translator)。 最开始NAT是运行在路由器上的一个功能模块。 最先提出的是基本的NAT，它的产生基于如下事实：一个私有网络（域）中的节点中只有很少的节点需要与外网连接（呵呵，这是在上世纪90年代中期提出的）。那么这个子网中其实只有少数的节点需要全球唯一的IP地址，其他的节点的IP地址应该是可以重用的。 因此，基本的NAT实现的功能很简单，在子网内使用一个保留的IP子网段，这些IP对外是不可见的。子网内只有少数一些IP地址可以对应到真正全球唯一的IP地址。-Forum on the principle of frequent discussion on P2P, but the discussion to the discussion, there is very little substance produced (source code). Oh, here on my own implementation of a source code to illustrate the principle of UDP through NAT. First of all, to introduce some basic concepts: NAT (Network Address Translators), Network Address Translation: NAT IP addresses are becoming more and more scarce in the circumstances, it is the main purpose of reuse in order to be able to address. NAT is divided into two categories, the basic NAT and NAPT (Network Address/Port Translator). Most are running at start NAT router on a function module. The first to propose that the basic NAT, it is the emergence of truth based on the following: a private network (domain) of nodes required only a few nodes and external network connection (Ha ha, this is up at mid-century and raised 90) . Well, this subnet in a matter of fact only a small number of nodes required of the world s only IP addresses, o Platform: |
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