apt-get install pptpd
nano /etc/pptpd.conf

localip 10.0.0.1
remoteip 10.0.0.100-200

nano /etc/ppp/chap-secrets

username pptpd password *

nano /etc/ppp/pptpd-options

ms-dns 8.8.8.8
ms-dns 8.8.4.4

service pptpd restart

nano /etc/sysctl.conf

net.ipv4.ip_forward = 1

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