With the advent of the information age, the development of enterprises are also increasingly showing industrial diversification, the structure of the distribution, management information features. Computer network technology continues to improve, expanding the scope of information management, both internal departments, suppliers or outside the enterprise, affiliates and outgoing personnel, are required to establish between the corporate headquarters with a fast, secure and stable network communication environment. How to establish secure communication with the external environment and the internal network between the network environment, remote access to enterprise branch offices outside the internal network resources, a lot of companies in the current building information network problems to be solvedKeyword: VPN , network , tunnel , safely，IPSec，GRE
廖小可可
