网络地址转换技术的实现与发展

网络地址转换（NAT）技术是解决当前Internet网络IP地址匮乏的一种有效手段，同时又是一项网络国界安全防范措施，本文在分析了NAT基本原理基础上，详细阐述了NAT网关的注册地址分配策略、路由策略、IP数据的修改以及安全和加密等技术细节，给出了NAT在网络层的实现策略，包括TCP／IP驱动系统的结构、IP协议在Linux中的实现和NAT技术在IP层的实现，最后，文章展望了NAT技术的发展趋势：端口地址转换PAT和NAT的跨主干网技术。

Implementation and development of network address translation technology

Network address translation (NAT) technology is an efficient way to solve the IP address depletion problem in the current Internet, and is also a security measurement of network border defense. Based on the analysis of NAT's basic principles, this paper expounds the details of the technologies, mainly on NAT gateway, including the registration address allocation strategy, the routing strategy, the modification of IP datagram, and security and encryption techniques. It also puts forward the implementation strategies of NAT in IP layer, which includes the structure of TCP/IP driver, the realization of IP protocols in Linux, and the realization of NAT technology in IP layer. Finally, the paper prospects the development trend of NAT technology, such as port address translation (PAT) and the cross backbone technology of NAT.