VPn Server issue

Question

Hello everybody.
I have an issue making my VPN Server work. here is my situation:
I have a router R1 with 2 ethernet interfaces
interface N°1 : 192.168.1.1/24
interface N°2 : 192.168.2.1/24
the first interface is connected to the subnet to which some computers and servers (DHCP,DNS,Active directory servers) are connected.
the second interface is connected to my VPN server.
the VPN server has 2 interfaces.
one connected to the intranet (precisely R1) with the ip 192.168.2.2 and the second has a public ip address.
the VPN server successfully get its pool of addresses from the dhcp server with the ip 192.168.1.4.
and since the VPN server use the interface with the ip 192.168.2.2 to reach the DHCP server it gets a subset of 192.168.2.0/24.
so I end up with a  VPN server who has an intranet interface that belongs to the same subnet as any connected vpn client.
the connection between the server and clients is established correctly and the clients get the correct ip addresses. and yet I can't ping any device except the VPN server interface.
so I captured the packets flow and I discovered that the ECHO message reach it's destination. The problem occur when the Router R1 try to forward the reply to the client.it send an ARP request but it don't get any response.
in this situation based on what a read on internet the VPN server is supposed to act as a proxy ARP replying with it's own MAC address on behalf of the vpn client and then routing the packet to it's destination.
when I configured the VPN server with a static pool from 192.168.3.0/24 and added a static route in R1 everything worked perfectly.
Thanks

Answer 1

Hi,
Could you clarify “so I end up with a 
VPN server who has an intranet interface that belongs to the same subnet as any connected vpn client.” Have you disable the 192.168.2.2 interface or make others action on it’s configuration?
•If the static IP address pool consists of ranges of IP addresses that are for a separate subnet, then you need to either enable an IP routing protocol on the remote access
server computer or add static IP routes consisting of the {IP Address, Mask} of each range to the routers of the intranet. If the routes are not added, then remote access clients cannot receive traffic from resources on the intranet.
•If the DHCP server is on the same subnet as the RRAS server, then you do not have to configure the DHCP relay agent. RRAS can find DHCP servers on the same subnet by using
broadcast network packets.
The related KB:
Configure the Way RRAS Assigns IP Addresses to VPN Clients
http://technet.microsoft.com/en-us/library/dd469667.aspx
Hope this helps.
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"“so I end up with a 
VPN server who has an intranet interface that belongs to the same subnet as any connected vpn client.” means that the interface of my server that is connected to my private network has an ip from 192.168.2.0/24 its the interface used to get to my network
ressources like the DHCP server.
the DHCP relay agent is configured correctly and my vpn server can contact the dhcp server.
when I used a static pool from 192.168.3.0/24 and added a static route to my router  everything work perfectly but when I configure my vpn server to get ip addresses
from DHCP server The vpn client can't access my intranet ressources even though it get a correct ip.