Install PPTP / PPP Proxy Server on CentOS 6

PPTP Proxy is an easy to setup proxy server that can be used as an OpenVPN alternative, and many small applications have options to utilize a PPTP proxy tunnel. In this guide you'll find out how to setup and configure a basie PPTP proxy server.

First update all of your installed packages. This isn't required but is a good thing to do beforehand.

yum update -y

Next install PPP and some required packages we need to setup the server.

yum install ppp perl wget nano -y

Now lets download the RPM for PPTPD server.

wget http://poptop.sourceforge.net/yum/stable/packages/pptpd-1.4.0-1.el6.x86_64.rpm

Install the rpm file that we just downloaded.

rpm -Uvh pptpd*

Now the PPTPD server is installed. Now we need to edit some settings in the pptpd configuration. We'll open the file with nano text editor.

nano /etc/pptpd.conf

Add the following two lines to this file and save it.

localip 0.0.0.0
remoteip 0.0.0.0

* change "localip 0.0.0.0" to the IP you want the pptpd server to bind to, change "remoteip 0.0.0.0" to the IP that you want clients to use when they are connected.

Once that file is saved, lets make a new file to specify the DNS servers that clients will use.

nano /etc/ppp/pptpd-options

Add the following lines to the file so clients use Google's DNS service.

ms-dns 8.8.8.8
ms-dns 8.8.4.4

Once the file is saved lets add a test user account. Edit the following file:

nano /etc/ppp/chap-secrets

Add the following line.

# client    server  secret          IP addresses
user1 pptpd password *

"user1" is the username to use, "password" is the client password is used, and "*" allows the client to connect from any IP.

Now we need to add some firewall rules to allow traffic passthrough.

iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -A INPUT -i eth0 -p gre -j ACCEPT

Next enable IPv4 packet forwarding. Edit the following file:

nano /etc/sysctl.conf

Find the following line:

net.ipv4.ip_forward = 0

Change it to:

net.ipv4.ip_forward = 1

Save the file that we just edited then reload the configuration with the following command.

sysctl -p

Now start the PPTPD service and add it to the startup list.

service pptpd start
chkconfig pptpd on

That's it! Now you can connect to your PPTPD proxy with a client or application that has an option for this type of proxy.