这是一个自动安装脚本，for 大便系列。比如 大便和ubuntu（版权不是我的，我也只是拿来改改） ：

#!/bin/bash

function installVPN(){
apt-get update
#remove ppp pptpd
rm -rf /etc/pptpd.conf
rm -rf /etc/ppp
apt-get -y remove ppp pptpd
apt-get -y install ppp pptpd iptables

#注意，这里的一些refuse-pap之类的要注意，如果不能连接首先改这里。
#如果一直出错，将require-mschap-v2和require-mppe-128 这两行加密注释掉，（对应源文件）
echo name pptpd >> /etc/ppp/pptpd-options
echo refuse-pap >> /etc/ppp/pptpd-options
echo refuse-chap >> /etc/ppp/pptpd-options
#refuse-mschap
echo require-mschap-v2 >> /etc/ppp/pptpd-options
echo require-mppe-128 >> /etc/ppp/pptpd-options
echo proxyarp >> /etc/ppp/pptpd-options
echo nodefaultroute >> /etc/ppp/pptpd-options
echo lock >> /etc/ppp/pptpd-options
echo nobsdcomp >> /etc/ppp/pptpd-options


echo ms-dns 8.8.8.8 >> /etc/ppp/pptpd-options
echo ms-dns 8.8.4.4 >> /etc/ppp/pptpd-options
echo ms-dns 4.3.2.1 >> /etc/ppp/pptpd-options

#写到pptpd.conf文件中
echo option /etc/ppp/pptpd-options >> /etc/pptpd.conf
echo logwtmp >> /etc/pptpd.conf
echo localip 192.168.99.1 >> /etc/pptpd.conf
echo remoteip 192.168.99.9-99 >> /etc/pptpd.conf

#这个最好只能处理一次。否则每次都会修改,以防万一，改两次吧。。第一次应该失败
sed -i 's/#net\.ipv4.ip_forward=0/net\.ipv4.ip_forward=1/' /etc/sysctl.conf
sed -i 's/#net\.ipv4.ip_forward=1/net\.ipv4.ip_forward=1/' /etc/sysctl.conf
#echo net.ipv4.ip_forward = 1 >> /etc/sysctl.conf
sysctl -p
#以下内容是for OPENVZ
#iptables -t nat -A POSTROUTING -s 192.168.99.0/24 -j SNAT --to-source `ifconfig | grep 'inet addr:'| grep -v '127.0.0' | cut -d: -f2 | awk 'NR==1 { print $1}'`
#sed -i 's/exit\ 0/#exit\ 0/' /etc/rc.local

#echo iptables -t nat -A POSTROUTING -s 192.168.99.0/24 -j SNAT --to-source `ifconfig | grep 'inet addr:'| grep -v '127.0.0' | cut -d: -f2 | awk 'NR==1 { print $1}'` >> /etc/rc.local
#echo exit 0 >> /etc/rc.local



# --- the sentence below was remarked By yanwen , what are you doing ??-----

}

function installOpenVZ(){
(installVPN)
iptables -t nat -A POSTROUTING -s 192.168.99.0/24 -j SNAT --to-source `ifconfig | grep 'inet addr:'| grep -v '127.0.0' | cut -d: -f2 | awk 'NR==1 { print $1}'`
sed -i 's/exit\ 0/#exit\ 0/' /etc/rc.local

echo iptables -t nat -A POSTROUTING -s 192.168.99.0/24 -j SNAT --to-source `ifconfig | grep 'inet addr:'| grep -v '127.0.0' | cut -d: -f2 | awk 'NR==1 { print $1}'` >> /etc/rc.local
echo exit 0 >> /etc/rc.local
(setDefaultUser)
}
function installXen(){
(installVPN)
iptables -t nat -A POSTROUTING -s 192.168.99.0/24 -o eth0 -j MASQUERADE
sed -i 's/exit\ 0/#exit\ 0/' /etc/rc.local

echo iptables -t nat -A POSTROUTING -s 192.168.99.0/24 -o eth0 -j MASQUERADE >> /etc/rc.local
echo exit 0 >> /etc/rc.local
(setDefaultUser)
}

function setDefaultUser(){
#默认用户
echo gouki \* 123456 \* >> /etc/ppp/chap-secrets
/etc/init.d/pptpd restart
}

function repaireVPN(){
echo "begin to repaire VPN";
mknod /dev/ppp c 108 0
/etc/init.d/pptpd restart
}

function addVPNuser(){
echo "input user name:"
read username
echo "input password:"
read userpassword
echo "${username} pptpd ${userpassword} *" >> /etc/ppp/chap-secrets
/etc/init.d/pptpd restart
}
function disableEncyption(){
sed -i 's/^require-mschap-v2/#require-mschap-v2/' /etc/ppp/pptpd-options
sed -i 's/^require-mppe-128/#require-mppe-128/' /etc/ppp/pptpd-options
/etc/init.d/pptpd restart
}
function enableEncyption(){
sed -i 's/^#require-mschap-v2/require-mschap-v2/' /etc/ppp/pptpd-options
sed -i 's/^#require-mppe-128/require-mppe-128/' /etc/ppp/pptpd-options
/etc/init.d/pptpd restart
}
echo "which do you want to?input the number."
echo "1. install Xen VPN service"
echo "2. install OpenVz VPN service"
echo "3. repaire VPN service"
echo "4. add VPN user"
echo "5. disable encryption"
echo "6. disable encryption"
read num

case "$num" in
[1] ) (installXen);;
[2] ) (installOpenVZ);;
[3] ) (repaireVPN);;
[4] ) (addVPNuser);;
[5] ) (disableEncyption);;
[6] ) (enableEncyption);;
*) echo "nothing,exit";;
esac

第一次写和改。连参数都不会。将就点了。。嗯。上面的内容复制起来比较麻烦，所以我做一个文件，可以直接下载：
放到自己的目录下，chmod a+x 这个文件。再执行就OK了。
你可以先看一下这个文件。。。以防万一
下载地址：21a964d1c161938b942054770a657e97