安装openVPN

参见

How To Set Up an OpenVPN Server on Ubuntu 16.04

如果想要开启内网访问

How to set up OpenVPN to let the VPN clients to access all the servers inside the server LAN?

如果只是要用来访问内网

在客户端的配置文件加入

route-nopull

route 10.8.1.0 255.255.255.0 vpn_gateway