PPTP

PPTP – Point-to-Point Tunneling Protocol – extends the Point to Point Protocol (PPP) standard for traditional dial-up networking. Which enables the secure transfer of data from a remote client to a private enterprise server by creating a virtual private network (VPN) across TCP/IP-based data networks. PPTP supports on-demand, multi-protocol, virtual private networking over public networks, such as the Internet.

PPTP and PPTPD insatallation on cpanel servers

1) Install PPP.

yum install ppp

2) Download the appropriate RPM from here (select required version of your centOS version).

wget http://poptop.sourceforge.net/yum/stable/rhel5/x86_64/pptpd-1.3.4-2.rhel5.x86_64.rpm 

3)Install the RPM.

rpm -ivh pptpd-1.3.4-2.rhel5.x86_64.rpm

4) Edit the file /etc/pptd.conf.

vim  /etc/pptpd.conf

Add the following lines to the fies at end.

localip 	xx.xx.xx.xx
remoteip	xx.xx.xx.xx

5) Second configuration file to be edited is /etc/ppp/options.pptpd

vim /etc/ppp/options.pptpd

Set DNS at ms-dns lines

ms-dns 8.8.8.8
ms-dns 8.8.4.4

6) Edit the file /etc/ppp/chap-secrets to add users.

vim /etc/ppp/chap-secrets
#secrets for authenticaion using CHAP
#client	server		secret		IP addresses
username pptpd password *

Firewall configuration

7) Edit /etc/sysctl.conf .

vim /etc/sysctl.conf 

Enable IP forwarding by editing the follwing line

net.ipv4.ip_forward=1

8) Load in sysctl settings from the file /etc/sysctl.conf .

/sbin/sysctl -p

9) Configuring IPtables for NAT

/sbin/service iptables start
/sbin/iptables -t nat -A POSTROUTING -o eth0 -s xx.xx.xx.xx/xx -j MASQUERADE
service iptables save        
Restart the pptp service
/sbin/sevice pptpd start
ckhkconfig pptpd on
csf -r

That’s all !!