Analysis Of Ipsec Protocol Architecture, Theory, And The Vpn Based On Ipsec Protocol And Formed

Developing rapidly in the recent years, the computer network has become the communication infrastructure of the human society. Its security was not noticed in the first few years when it came into being and was used to transmit email among the researchers in the university and to share printer among collaborative employees, but its importance becomes more and more outstanding along with its more and more value in the social life.Security of network has been a hot topic of research. The protection to the information, which is easy to be peeked, modified and counterfeited, is to offer secrecy, integrity and source verification. Virtual Network is an effective device to provide such protections. The technology of VPN is being popularized. It links consumers,subsidiary companies and commerce-partners to corporation through internet and provides secrecy, integrity and identity verification. VPN can resist attack from internet and economizes money.The device of VPN which is between protected subnet and router can keep communication of network away from attack if more than two devices are used all together. Two VPN devices negotiate about shared parameter in order to establish a secure tunnel when security policies were configured. The data in the protected subnet are not encrypted, but are encrypted in the tunnel in order to keep its secrecy, integrity.The technology of VPN can be used in the every layer of net-model, for example: Data Link Layer, Network Layer and Session Layer . This article is about the implement of VPN based on IPSEC because data will be encapsulated IP-pack before data are transmitted, moreover, the operation of data in the network layer can offer secure and transparent service for up layer.It is very detail that article is about IPSEC VPN.