[Grefyne]

I am having a routing problem between my PPTP VPN network and my home network. I hope someone can offer some suggestions.

The PPTP VPN is connecting without any difficulty and I am able to ping both the IP address provided by the VPN to the router and the VPN network side IP address while SSH’d into the router. However, I am not able to other IPs on the VPN side of the connection.

However, if I try to ping from a computer on the home network; I can ping the IP address provided to by the VPN but not the VPN network side.

For example:

Home Network
172.16.112.0
255.255.255.0
GW IP: X.X.X.X (ISP/DHCP)
Router: 172.16.112.1

VPN Network
192.168.0.0
255.255.0.0
VPN Side: 192.168.220.200

VPN Provided IP: (Dynamic)
192.168.220.201

Home Computer
172.16.112.2

From 172.16.112.2, I can ping 192.168.220.201 fine.
From 172.16.112.2, I cannot ping 192.168.220.200 or any other VPN side address.

While SSH’d into the router I can ping 192.168.220.201 fine.
While SSH’d into the router I can ping 192.168.220.200 fine.
While SSH’d into the router I cannot ping 192.168.220.6 or any other IP on the VPN side.

I want to continue to use the ISP IP for my normal internet traffic but I want to route all 192.168.x.x traffic through the VPN connection. Please help if you can.

[Grefyne]

The NAT is enabled on the PPTP VPN config. However, I am unsure of how to verify NAT beyond that.

[Grefyne]

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 X.X.X.1 0.0.0.0 UG 0 0 0 vlan2
X.X.X.0 0.0.0.0 255.255.255.0 U 0 0 0 vlan2
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 br0
172.16.112.0 0.0.0.0 255.255.255.0 U 0 0 0 br0
192.168.220.200 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0
Y.Y.Y.Y X.X.X.1 255.255.255.255 UGH 0 0 0 vlan2

The X.X.X and Y.Y.Y addresses are ISP related.

[Grefyne]

The VPN server is Windows Server 2008 R2 using RRAS. I do have access to the network servers including the RRAS server. My role is database related so I am hesitant to make any changes to that server, but I can verify that the VPN connection is operating.

[Grefyne]

like so?

route add -net 192.168.0.0 netmask 255.255.0.0 dev ppp0

[Grefyne]

That seems to almost do the trick.

I can now ping any address within the 192.168.0.0 network while SSH'd. However the computer on the 172.16.112.0 network still cannot.

[Grefyne]

For example:

pinging from computer on 172.16.112.0 network.

192.168.220.201 OK
192.168.220.200 NO
192.168.220.6 NO

[Grefyne]

Chain POSTROUTING (policy ACCEPT 2937 packets, 202K bytes)
pkts bytes target prot opt in out source destination
18976 1821K SNAT 0 -- * vlan2 172.16.112.0/24 0.0.0.0/0 to:XX.XXX.X.XXX
0 0 MASQUERADE 0 -- * * 0.0.0.0/0 0.0.0.0/0 mark match 0x80000000/0x80000000

[Grefyne]

It is/was active and the NAT is enabled.

[Grefyne]

That works. Excellent work, thank you.

Now I just need to figure out how to run those 2 commands when the VPN connects.

[Grefyne]

Thank you for your help. I will see if that works. I suspect its a bad configuration on the other side of the VPN, i have heard of others at work complaining about the VPN.