Windows XP SP2 causes VPN routing problem

[Joe S]

We are running a Windows 2003 domain. I have a Windows
2000 member server setup to receive PPTP VPN connections
from remeote clients which run various os - but mostly
w2k
and XP. The VPN server has some static routes on it that
point to a remote network that the VPN clients need to
access. The problem is any VPN client running XP SP2 can
not access that remote network via our corporate network.
The XP firewall has been turned off as well. Has anyone
seen this? Is this by design? FYI - We have 'use default
gateway on remote netork' unchecked. If it is checked,
then the routing works correctly. This was not necessary
on any other ms os's including xp sp1. I know the easy
answer is just to check it off but our remote clients
will overwhelm our internet bandwidth because all of
their internet activity will be directed to us.

Ex. network:

Remote Client (ISP assigned IP address) --> connects to
Corporate Network (10.3.10.0). VPN Client receieves DHCP
address from VPN server of 10.3.10.25.

VPN server has static route entered in RRAS under static
route of 10.2.0.0 (dest), 10.3.10.221 (gateway router),
interface LAN. VPN server only has 1 nic card.

With this setup, a remote VPN client running anything but
XP SP2 can tracert or ping any address on the 10.2.0.0
network. If I do it from a XP SP2 client, it does not
work.

Thanks,
Joe

 

[Bill Grant]

I am not sure why SP2 would make any difference to this. It is basically
a routing issue.

When you clear the "use default gateway.." box, you disable the default
route to your VPN server. Only a subnet route is then set up for the VPN
link. See KB 254231 .

If the extra subnet you want to access is not included in this, the
traffic will not go through the VPN link - it will go out to the Internet.
You will need extra routing on the client to send it through the VPN link.