PPTP VPN Centos

Install PPTP VPN Server on your VPS Centos

Introduction

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In this article we show you how to install and properly configure a PPTP VPN server in your virtual private server (VPS). With this VPN you'll have access to transfering your data encrypted and using a virtual ethernet interface that uses your Virtual Private Server's IP address. This tunneling technology is compatible with several devices like desktop operating systems, mobile phones and tables. We will be using Centos 6.4 64 Bits as our host operating system.

First make sure you begin with a clean install by removing any previously installed packages:

yum remove -y pptpd ppp

iptables --flush POSTROUTING --table nat

iptables --flush FORWARD

rm -rf /etc/pptpd.conf

rm -rf /etc/ppp

Initial PPTP Packages

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First, install the poptop package from sourceforge:

rpm -Uhv http://poptop.sourceforge.net/yum/stable/rhel6/pptp-release-current.noarch.rpm

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

Now, we need to enable IP forwading, set internal IP addresses and point the DNS Servers that will be used by the pptp server:

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

Then, create your users credentials for the PPTP server. This credentials will be used to log in to the PPTP server on every client/device you connect from:

vi /etc/ppp/chap-secrets

Your chap-secrets file should look like this:

# Secrets for authentication using CHAP

# client        server  secret                  IP addresses

yourusername    pptpd   yourpassword            *

Save and close the file.

Next, you need to add the following iptables rules in order to open the correct ports and properly forward the data packets:

# VPN rules (pptpd)

iptables -A INPUT -i eth0 -p tcp --dport 1723 -j ACCEPT

iptables -A INPUT -i eth0 -p gre -j ACCEPT

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

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

Save and restart your iptables firewall:

service iptables save

service iptables restart

Make sure you load your iptables after every reboot:

chkconfig iptables on

chkconfig pptpd on

And finally, restart iptables and pptpd services:

service iptables start

service pptpd start