PPTP VPN Server issue : server = centOS & client = windows 7

pptpvpn

I have a CentOS server configured as a PPTP VPN Server.

The client is a Windows 7 with "Use default gateway on remote network" in advanced TCP/IPv4 properties enable. He can connect to CentOS without any problem and can access to:

  • The Box of his ISP (http://192.168.1.254/)
  • The CentOS server
  • The website which is hosted by the server (through http://)

But he canNOT access any other web service (google.com or 74.125.230.224)

I am a beginner with web servers so I do not know what can cause this problem.

  • Note 0 : The Windows 7 user must be able to access the whole internet through the CentOS PPTP proxy.
  • Note 1 : With "Use default gateway on remote network" in advanced TCP/IPv4 UNCHECKED it is the same problem
  • Note 2 : With "Use default gateway on remote network" in advanced TCP/IPv4 UNCHECKED AND "disable class based route addition" CHECKED the Win 7 can access google but with the ISP IP (no use of the VPN…)
    See Screenshot
  • Note 3 : I have made a echo 1 > /proc/sys/net/ipv4/ip_forward and a iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

Best Answer

I have found the solution.

There was a script in my server which did, at every reboot : echo 0 > /proc/sys/net/ipv4/ip_forward and a REMOVE(iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE) ...

I added a startup shell with :

echo 1 > /proc/sys/net/ipv4/ip_forward

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

Everything works like a charm !

Related Topic