VPN Server behind a NAT enabled router

Hello All,
I want to setup a VPN connection for our intranet. We have SBS 2000
server setup with ISA firewall, The SBS 2000 is connected to the internet
using a DSL Router Dlink 504. The Router has NAT enabled on it, and I have
Port redirect enabled to forward port 1723 to the SBS2000 server. I am able
to connect and test the VPN from within our network but I am not able to
connect to the VPN from outside our network. Why I try to connect to the VPN
Server from outside our network, the Windows XP client hangs on login
screen, and keeps on saying that its authenticating the username and
password. How can I get the VPN running from outside out network, what needs
to be done to enable the VPN access with the current setup.
Regards,
Imran.

this may help. quoted form http://www.ChicagoTech.net
Permits network traffic between two networks by using Policy rules
To permits network traffic between two networks in both directions, you may
want to create Policy Rule. This behavior might be helpful when you
configure VPN client connections.
--
For more and other information, go to http://www.ChicagoTech.net


Don't send e-mail or reply to me except you need consulting services.
Posting on MS newsgroup will benefit all readers and you may get more help.

Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN, Anti-Virus, Tips & Troubleshooting on
http://www.ChicagoTech.net
Networking Solutions, http://www.chicagotech.net/networksolutions.htm
VPN Solutions, http://www.chicagotech.net/vpnsolutions.htm
VPN Process and Error Analysis, http://www.chicagotech.net/VPN%20process.htm
VPN Troubleshooting, http://www.chicagotech.net/vpn.htm
This posting is provided "AS IS" with no warranties.
"Imran Aziz" <(E-Mail Removed)> wrote in message
news:e%(E-Mail Removed)...
> Hello All,
> I want to setup a VPN connection for our intranet. We have SBS 2000
> server setup with ISA firewall, The SBS 2000 is connected to the internet
> using a DSL Router Dlink 504. The Router has NAT enabled on it, and I have
> Port redirect enabled to forward port 1723 to the SBS2000 server. I am
> able to connect and test the VPN from within our network but I am not able
> to connect to the VPN from outside our network. Why I try to connect to
> the VPN Server from outside our network, the Windows XP client hangs on
> login screen, and keeps on saying that its authenticating the username and
> password. How can I get the VPN running from outside out network, what
> needs to be done to enable the VPN access with the current setup.
> Regards,
> Imran.
>

Thanks a lot for your response. It was my DSL Dlink 504 router that was
creating the problem, as it does not allow GRE 47 protocol to pass through
it. Creating a DMZ is the only way to get it working.
Imran.
"Robert L [MS-MVP]" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> this may help. quoted form http://www.ChicagoTech.net
> Permits network traffic between two networks by using Policy rules
> To permits network traffic between two networks in both directions, you
> may want to create Policy Rule. This behavior might be helpful when you
> configure VPN client connections.
> --
> For more and other information, go to http://www.ChicagoTech.net
>
>
> Don't send e-mail or reply to me except you need consulting services.
> Posting on MS newsgroup will benefit all readers and you may get more
> help.
>
> Bob Lin, MS-MVP, MCSE & CNE
> Networking, Internet, Routing, VPN, Anti-Virus, Tips & Troubleshooting on
> http://www.ChicagoTech.net
> Networking Solutions, http://www.chicagotech.net/networksolutions.htm
> VPN Solutions, http://www.chicagotech.net/vpnsolutions.htm
> VPN Process and Error Analysis,
> http://www.chicagotech.net/VPN%20process.htm
> VPN Troubleshooting, http://www.chicagotech.net/vpn.htm
> This posting is provided "AS IS" with no warranties.
> "Imran Aziz" <(E-Mail Removed)> wrote in message
> news:e%(E-Mail Removed)...
>> Hello All,
>> I want to setup a VPN connection for our intranet. We have SBS 2000
>> server setup with ISA firewall, The SBS 2000 is connected to the internet
>> using a DSL Router Dlink 504. The Router has NAT enabled on it, and I
>> have Port redirect enabled to forward port 1723 to the SBS2000 server. I
>> am able to connect and test the VPN from within our network but I am not
>> able to connect to the VPN from outside our network. Why I try to connect
>> to the VPN Server from outside our network, the Windows XP client hangs
>> on login screen, and keeps on saying that its authenticating the username
>> and password. How can I get the VPN running from outside out network,
>> what needs to be done to enable the VPN access with the current setup.
>> Regards,
>> Imran.
>>
>
>