Research And Implementation Of Virtual Private Network Vpn

The Virtual Private Network (VPN) , a new network conception , has been proposed in recent years , as a result of the rapid development of Internet, the gradual globalization and informization of social economy and more and more sharpening problems of network security . It is of great practical value for the network security and information security to study the solution to the realization of VPN . At present four kinds of technologies have mainly been adopted to realization of VPN, including tunneling technology , encryption & decryption technology, key management technology and user & facility identity authentication technology.Linux is an operating system which publishes the source code. Though it has developed less than ten years , yet it has gained wide popularity in the field of computer for its high efficiency , good stability and rapid development . In Linux , the kernel is easy to be reduced , the network protocal works efficiently and all the source codes can be obtained , thus it is an ideal platform to construct the VPN system .This article begins with a profound research into the kinds of key technology , with its emphasis on the discussion of realizing the tunneling technology and encryption technology , and then a deep analysis was made into the structure of Linux' s kernel ; at last a VPN resolving scheme based on Linux' s kernel was put forward with a detailed description of systematic realization. In the process of designing and realizing the system , the author , through revising the kernel source code of Linux' s system , resolved successfully the transparent embedding of VPN equipment , the support to various kinds of encryption identity algorithm , the driver of encryption equipment based on PCI bus , the resource competition of encryption equipment , the automatic communication of the encryption keys , which give security N stabilityN high-efficiency and transparency to the total system .The article not only resolved the relative problems concerningthe network security, but provided for users a complete resolving scheme of constructing a private network with internet. Moreover, some relative technologies have already been put into production and the products have been applied to the user' s actual network successfully with high practical and popularizing value.