IP address assignment for VPN computers

Hi all...

I have a LAN in a site that connects to Internet by mean of an ISP. The
server in that LAN shares Internet access to all LAN computers using
ICS/ICF. Since I have ICS, the server was assigned the IP 192.168.0.1. Let's
name this site as S1.

I have other site that connects to Internet using other ISP. The server
shares Internet using RRAS/NAT configured as a VPN. This server is also
assigned IP 192.168.0.1. Let's name this site as S2.

When I establish the VPN connection from S1 (the client) to S2, all S1 LAN
computers lost connectivity to Internet (but not among them). I think it is
because of IP conflict among servers of S1 and S2..

What is the best way to manage this to work?

Thanks a lot in advance.

Jaime

Not sure which VPN you are using, but, some will disable ALL other
connections to/from the VPN client machine EXCEPT the VPN while it is in
operation. Sounds like this is what is happening. That is by design.

Maybe if you explained exactly what you want to do it would help.

-Frank

"Jaime Stuardo" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> Hi all...
>
> I have a LAN in a site that connects to Internet by mean of an ISP. The
> server in that LAN shares Internet access to all LAN computers using
> ICS/ICF. Since I have ICS, the server was assigned the IP 192.168.0.1.
> Let's name this site as S1.
>
> I have other site that connects to Internet using other ISP. The server
> shares Internet using RRAS/NAT configured as a VPN. This server is also
> assigned IP 192.168.0.1. Let's name this site as S2.
>
> When I establish the VPN connection from S1 (the client) to S2, all S1 LAN
> computers lost connectivity to Internet (but not among them). I think it
> is because of IP conflict among servers of S1 and S2..
>
> What is the best way to manage this to work?
>
> Thanks a lot in advance.
>
> Jaime
>
>
>

I would use NAT instead of ICS. quoted from http://www.chicagotech.net/nat.htm

Difference between ICS and NAT
To connect a windows 2000/2003 network to the Internet, you may use one of two methods: ICS and NAT. Both ICS and NAT provide translation, addressing, and name resolution services to the network hosts.

ICS is designed to provide a single step of configuration (a single check box) on the computer running Windows 2000/2003 to provide a translated connection to Internet for all of the hosts on the network. However, once enabled, Internet connection sharing does not allow further configuration beyond the configuration of applications and services on the network.

NAT routing protocol is designed to provide maximum flexibility in the configuration of the computer running Windows 2000 Server to provide a translated connection to Internet. NAT requires more configuration steps; however, each step of the configuration is customizable. The NAT protocol allows for ranges of IP addresses from ISP and the configuration of the range of IP addresses allocated to the network hosts.


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
How to Setup Windows, Network, Remote Access on http://www.HowToNetworking.com
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.


"Jaime Stuardo" <(E-Mail Removed)> wrote in message news:%(E-Mail Removed)...
Hi all...

I have a LAN in a site that connects to Internet by mean of an ISP. The
server in that LAN shares Internet access to all LAN computers using
ICS/ICF. Since I have ICS, the server was assigned the IP 192.168.0.1. Let's
name this site as S1.

I have other site that connects to Internet using other ISP. The server
shares Internet using RRAS/NAT configured as a VPN. This server is also
assigned IP 192.168.0.1. Let's name this site as S2.

When I establish the VPN connection from S1 (the client) to S2, all S1 LAN
computers lost connectivity to Internet (but not among them). I think it is
because of IP conflict among servers of S1 and S2..

What is the best way to manage this to work?

Thanks a lot in advance.

Jaime

Robert, if you can recall.... I am the guy who couldn't configure NAT in S1, but I could in S2, since in S2 the second NIC was really Internet.

Jaime
"Robert L [MS-MVP]" <(E-Mail Removed)> wrote in message news:eh4I%(E-Mail Removed)...
I would use NAT instead of ICS. quoted from http://www.chicagotech.net/nat.htm

Difference between ICS and NAT
To connect a windows 2000/2003 network to the Internet, you may use one of two methods: ICS and NAT. Both ICS and NAT provide translation, addressing, and name resolution services to the network hosts.

ICS is designed to provide a single step of configuration (a single check box) on the computer running Windows 2000/2003 to provide a translated connection to Internet for all of the hosts on the network. However, once enabled, Internet connection sharing does not allow further configuration beyond the configuration of applications and services on the network.

NAT routing protocol is designed to provide maximum flexibility in the configuration of the computer running Windows 2000 Server to provide a translated connection to Internet. NAT requires more configuration steps; however, each step of the configuration is customizable. The NAT protocol allows for ranges of IP addresses from ISP and the configuration of the range of IP addresses allocated to the network hosts.


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
How to Setup Windows, Network, Remote Access on http://www.HowToNetworking.com
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
This posting is provided "AS IS" with no warranties.


"Jaime Stuardo" <(E-Mail Removed)> wrote in message news:%(E-Mail Removed)...
Hi all...

I have a LAN in a site that connects to Internet by mean of an ISP. The
server in that LAN shares Internet access to all LAN computers using
ICS/ICF. Since I have ICS, the server was assigned the IP 192.168.0.1. Let's
name this site as S1.

I have other site that connects to Internet using other ISP. The server
shares Internet using RRAS/NAT configured as a VPN. This server is also
assigned IP 192.168.0.1. Let's name this site as S2.

When I establish the VPN connection from S1 (the client) to S2, all S1 LAN
computers lost connectivity to Internet (but not among them). I think it is
because of IP conflict among servers of S1 and S2..

What is the best way to manage this to work?

Thanks a lot in advance.

Jaime

Hi Frankster,

I have this configuration:

| LAN S1 | -------------------[ INTERNET ] --------------------- | LAN S2 |

The idea here is to make LAN S1 and LAN S2 to act as if they were the same
LAN. For example, the server (that shares Internet with other LAN computers)
in LAN S1 is a development server, which stores documents and projects we
develop. A PC in LAN S2 needs to browse S1 computers using mapped drives so
that for S2 LAN PC's transparently connect a S1 LAN PC's as if it were on
the same LAN. Please, don't recommend the usage of WebDav since it doesn't
work in my case. I know that this is possible using VPN and it works but the
problem of IP assignment.

So, I need to configure a VPN that doesn't disable other connections. I
think this VPN doesn't do it since I can browse Internet from the server,
but I think the problem is that both server in S1 and S2 has it's internal
IP address of 192.168.0.1.

Thanks
Jaime

"Frankster" <(E-Mail Removed)> wrote in message
news:nOidnbGeOpkyhePfRVn-(E-Mail Removed)...
> Not sure which VPN you are using, but, some will disable ALL other
> connections to/from the VPN client machine EXCEPT the VPN while it is in
> operation. Sounds like this is what is happening. That is by design.
>
> Maybe if you explained exactly what you want to do it would help.
>
> -Frank
>
> "Jaime Stuardo" <(E-Mail Removed)> wrote in message
> news:%(E-Mail Removed)...
>> Hi all...
>>
>> I have a LAN in a site that connects to Internet by mean of an ISP. The
>> server in that LAN shares Internet access to all LAN computers using
>> ICS/ICF. Since I have ICS, the server was assigned the IP 192.168.0.1.
>> Let's name this site as S1.
>>
>> I have other site that connects to Internet using other ISP. The server
>> shares Internet using RRAS/NAT configured as a VPN. This server is also
>> assigned IP 192.168.0.1. Let's name this site as S2.
>>
>> When I establish the VPN connection from S1 (the client) to S2, all S1
>> LAN computers lost connectivity to Internet (but not among them). I think
>> it is because of IP conflict among servers of S1 and S2..
>>
>> What is the best way to manage this to work?
>>
>> Thanks a lot in advance.
>>
>> Jaime
>>
>>
>>
>
>

You will not be able to do this with a VPN connection if both subnets
are using the same IP subnet.

What you are setting up is a LAN to LAN (also called router to router)
VPN. The VPN connection links the sites, and the RRAS routers forward
traffic between the two subnets across the link. Because it is a routed
connection, the two sites must be in different subnets. It will not work as
a bridge. (A bridge is a connection between segments which are in the same
IP subnet).

There is lots of info on router to router VPN in the help files. If you
need more info, look at www.microsoft.com/vpn .

Jaime Stuardo wrote:
> Hi Frankster,
>
> I have this configuration:
>
>> LAN S1 | -------------------[ INTERNET ] --------------------- | LAN
>> S2 |
>
> The idea here is to make LAN S1 and LAN S2 to act as if they were the
> same LAN. For example, the server (that shares Internet with other
> LAN computers) in LAN S1 is a development server, which stores
> documents and projects we develop. A PC in LAN S2 needs to browse S1
> computers using mapped drives so that for S2 LAN PC's transparently
> connect a S1 LAN PC's as if it were on the same LAN. Please, don't
> recommend the usage of WebDav since it doesn't work in my case. I
> know that this is possible using VPN and it works but the problem of
> IP assignment.
> So, I need to configure a VPN that doesn't disable other connections.
> I think this VPN doesn't do it since I can browse Internet from the
> server, but I think the problem is that both server in S1 and S2 has
> it's internal IP address of 192.168.0.1.
>
> Thanks
> Jaime
>
> "Frankster" <(E-Mail Removed)> wrote in message
> news:nOidnbGeOpkyhePfRVn-(E-Mail Removed)...
>> Not sure which VPN you are using, but, some will disable ALL other
>> connections to/from the VPN client machine EXCEPT the VPN while it
>> is in operation. Sounds like this is what is happening. That is by
>> design. Maybe if you explained exactly what you want to do it would help.
>>
>> -Frank
>>
>> "Jaime Stuardo" <(E-Mail Removed)> wrote in message
>> news:%(E-Mail Removed)...
>>> Hi all...
>>>
>>> I have a LAN in a site that connects to Internet by mean of an ISP.
>>> The server in that LAN shares Internet access to all LAN computers
>>> using ICS/ICF. Since I have ICS, the server was assigned the IP
>>> 192.168.0.1. Let's name this site as S1.
>>>
>>> I have other site that connects to Internet using other ISP. The
>>> server shares Internet using RRAS/NAT configured as a VPN. This
>>> server is also assigned IP 192.168.0.1. Let's name this site as S2.
>>>
>>> When I establish the VPN connection from S1 (the client) to S2, all
>>> S1 LAN computers lost connectivity to Internet (but not among
>>> them). I think it is because of IP conflict among servers of S1 and
>>> S2.. What is the best way to manage this to work?
>>>
>>> Thanks a lot in advance.
>>>
>>> Jaime