Linux-based Vpn Software In Applied Research, The Campus Network

Anyang Institute of Technology has acquired thirty two IP addresses in total from China Netcom; it cannot meet the need of assigning public address to every user in the campus net at all. So NAT technology was applied for the users to access the Internet, that means IP private address was assigned to the net users at present, and this technical scheme brought a new problem, it's impossible for those users out of the campus to access resources constructed based on the IP private address. In order to find an effective solution to this problem, A Linux-based VPN system is designed a at the gateway of campus net, with this utility system, people outside the campus can access internal resources of campus net easily and conveniently.This Linux-based VPN system uses a PPTP(point to point tunnel protocol) framework, not only can it provide an encryption communication approach between the PPTP client and the PPTP server, but more importantly , it is supported widely by Microsoft and other company, and still, we construct a VPN system which supporte multiprotocol. Based on this framework, we develope the VPN user management system with B/S three-tier model, the user management system is developed by PHP program language, and MYSQL database is adopted at the backend, which is especially suitable for small application system. The WEB application system use APACHE as WEB server; it provide a more stable and safer running platform compared with IIS (Internet Information Server). In order to enhance the security control of VPN system, IPTABLES techniques is used in developing rules of access, not only can it serve to the process of user data transferring, but also it is a safeguard against attacks and intrusions which come from external network, This system ensure better and safer running.The Linux-based VPN system has been run smoothly over half a year in the campus net of Jiangxi University of Finance & Economics. And the test result is: It has 110 registered users, It's peak load is about 10 people and the max CPU usage is about 70 percents,It runs smoothly and there is no intrusion which was caught. This application system has a friendly user interface, and it's really safe. Most importantly is that it can save lots of money compared with those VPN devices designed for specific purposes to the tune which are several thousands even tens of thousands in price, in one word, this system should be widely promoted.