The Research Of VPN Technology Based On CAN

VPN is the technology of building a intranet based on the public network with the support of Tunneling technology, Encapsulation and Authentication methods. A VPN is virtual in that it has no corresponding physical network but rather shares physical circuits with other traffic. A VPN is private in that it isolates Internet traffic with routing and secures it with encryption. That is to say, it is realizable to connect the intranet to anywhere. Not only the problem of privacy protection, safety property and manageability can be smoothed out, but also the cost of the network can be brought down. In fact, the technology of VPN can also be used in the private net. Being applied to CAN, VPN can break the regional limit of the CAN or give better administration ways and means of the CAN. After introducing the correlative knowledge of VPN, such as TCP/IP protocols, Encryption technology and so on, the article discusses in detail the IPsec protocol and the two main protocols of VPN: PPTP and L2TP. And then, according to the actual network structure and application situation, the article comes up with an implement plan of VPN based on CAN. With the plan, not only a virtual private network will be build between the two campus areas, the regional area of accessing the servers in the private CAN will be extended to wherever can connect to the Internet, but also the administration of the resource in the private CAN will be more easy and more reasonable. At last, the article gives a sample of building a VPN server with the RRAS of Windows 2000 OS based on the given plan. The procedure of accessing to the VPN server is monitored with the help of the "Microsoft Network Monitor" . The analysis based on the monitoring result provides the safety property of the VPN communication, and verifies the availability of the plan to some extent.