随着互联网的快速发展，企事业单位和个人越来越多地通过VPN 进行网络访问，但是VPN 访问量的增加会 给服务器带来巨大的压力，而且频繁的访问也会给服务器的数据安全带来新的威胁。如何在复杂的网络环境下保障VPN 的 安全性，是本文探讨的重点。

With the rapid development of the Internet, more and more enterprises and individuals access the network through VPN. But the increase of VPN access to the server will bring with tremendous pressure, and frequent access to the server will give new threats to data security. How to protect the security of VPN in the complex network environment is the key point of this paper.