pptpd
yum install -y ppp pptp pptpd iptables
# ms-dns
vi /etc/pptpd.conf
# local ip
vi /etc/ppp/options.pptpd
# vpn pptpd 123456 *
vi /etc/ppp/chap-secrets
# ip_forward = 1
vi /etc/sysctl.conf
sysctl -p
# iptables
iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -o venet0 -j MASQUERADE
# start
service pptpd start
service iptables save
chkconfig pptpd on