Very fast urgent setup PPTP VPN Server on Debian system

sudo apt-get update
sudo apt-get upgrade

Add to /etc/network/interfaces

# VPN
auto eth0:1
iface eth0:1 inet static
address 192.168.0.1
netmask 255.255.255.0
post-up /etc/nat

sudo service networking restart

Add to /etc/resolv.conf

nameserver 8.8.8.8
nameserver 8.8.4.4

And add to /etc/nat

#!/bin/sh
echo 1 > /proc/sys/net/ipv4/ip_forward # Enable forwarding
iptables -t nat -A POSTROUTING -s 192.168.0.0/24  -o eth0 -j MASQUERADE

sudo chmod +x /etc/nat

sudo apt-get install pptpd

Edit /etc/pptpd.conf

option /etc/ppp/pptpd-options 
localip 192.168.0.1
remoteip 192.168.0.100-200

And edit /etc/ppp/pptpd-options

auth
name pptpd
refuse-pap
refuse-chap
refuse-mschap
require-mschap-v2
require-mppe-128
ms-dns 8.8.8.8
ms-dns 8.8.4.4
proxyarp
nodefaultroute
debug
lock
nobsdcomp

Add accounts to /etc/ppp/chap-secrets

# client server secret IP addresses
user pptpd password "*"

sudo service pptpd restart

That's all, folks! 

But it's best to spend more time and configure OpenVPN ;-)

Enjoy and stay tuned!