如何在CentOS/UbuntuVPS上安装OpenVPN

利用sh安装OPENVPN，除去锁碎配置，快速搭建安全专属通道。

下载openvpn-install.sh并安装以及赋予x权限
shell > wget http://git.io/vpn --no-check-certificate -O openvpn-install.sh; chmod +x openvpn-install.sh;
安装openvpn-install.sh
Centos : sh openvpn-install.sh
Ubuntu : sudo openvpn-install.sh

注意事项
First I need to know the IPv4 address of the network interface you want OpenVPN
listening to.
IP address: 1.2.3.4 //本机IP

What port do you want for OpenVPN?
Port: 1194 //默认VPN端口

What DNS do you want to use with the VPN?
1) Current system resolvers
2) OpenDNS
3) Level 3
4) NTT
5) Hurricane Electric
6) Google
DNS [1-6]: 6 //按6设置google为DNS,默认是1

Finally, tell me your name for the client cert
Please, use one word only, no special characters
Client name: client-vpn //配置客户端VPN名称

Okay, that was all I needed. We are ready to setup your OpenVPN server now
Press any key to continue... //按任意键开始安装
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Your client config is available at ~/client-vpn.ovpn //找到这个配置文件下载到本地
If you want to add more clients, you simply need to run this script another time!

查看下OpenVPN运行状态
shell > ps ax|grep openvpn
会看的这下这些
16103 ? Ss 0:00 /usr/sbin/openvpn --daemon --writepid /var/run/openvpn/server.pid --cd /etc/openvpn --config server.conf --script-security 2
16120 pts/0 S+ 0:00 grep openvpn
检查sysctl.conf并保存
shell > vi /etc/sysctl.conf
net.ipv4.ip_forward = 1
shell > sysctl -p /etc/sysctl.conf

iptables nat 地址转换
iptables -t nat -A POSTROUTING -s 1.2.3.4/24 -o eth0 -j MASQUERADE
到这里基本OK了，下面就是下载openvpn-install安装，然后把刚才从服务器上下载下来的client-vpn.ovpn文件放到C:\Program Files(x86)\OpenVPN\config\下面，启动OpenVPN GUI，右击Connect经行连接。