在日常生活中我们用到vpn的地方很多，比如:脸谱，推特，youtube,最近谷歌也被墙.
对于有独立vps的用户来说，装一个vpn是非常不å错的选择，但是大多数厂商不允许搭建公共vpn。

1.判断你的vps是否可以搭建vpn.

下面开始安装咯：

yum remove -y pptpd ppp

iptables --flush POSTROUTING --table nat

iptables --flush FORWARD

rm -rf /etc/pptpd.conf

rm -rf /etc/ppp

arch=`uname -m`

wget http://poptop.sourceforge.net/yum/stable/packages/pptpd-1.4.0-1.el6.$arch.rpm

yum -y install make libpcap iptables gcc-c++ logrotate tar cpio perl pam tcp_wrappers dkms kernel_ppp_mppe ppp

rpm -Uvh pptpd-1.4.0-1.el6.$arch.rpm

mknod /dev/ppp c 108 0

echo 1 > /proc/sys/net/ipv4/ip_forward 

echo "mknod /dev/ppp c 108 0" >> /etc/rc.local

echo "echo 1 > /proc/sys/net/ipv4/ip_forward" >> /etc/rc.local

echo "localip 172.16.36.1" >> /etc/pptpd.conf

echo "remoteip 172.16.36.2-254" >> /etc/pptpd.conf

echo "ms-dns 8.8.8.8" >> /etc/ppp/options.pptpd

echo "ms-dns 8.8.4.4" >> /etc/ppp/options.pptpd

pass=`openssl rand 6 -base64`

if [ "$1" != "" ]

then pass=$1

fi

echo "vpn pptpd ${pass} *" >> /etc/ppp/chap-secrets

iptables -t nat -A POSTROUTING -s 172.16.36.0/24 -j SNAT --to-source `ifconfig  | grep 'inet addr:'| grep -v '127.0.0.1' | cut -d: -f2 | awk 'NR==1 { print $1}'`

iptables -A FORWARD -p tcp --syn -s 172.16.36.0/24 -j TCPMSS --set-mss 1356

service iptables save

chkconfig iptables on

chkconfig pptpd on

service iptables start

service pptpd start

echo "VPN service is installed, your VPN username is vpn, VPN password is ${pass}"