VPN - When connected from remote location, why is the 'Server IP Address' not the actual server's IP address?

Hi All,

This is just an 'out of interest' type question.

I connect to our SBS 2003 Premium server using a VPN connection, from
a Win XP Home client

If I click on the connection icon in the task bar, and select the
'details' tab, it lists the 'Server IP Address' as 10.0.0.XX (where XX
is greater than 10).

However, the actual server I am connecting to has an IP in the range
(10.0.0.1 to 10.0.0.9)

What is going on there?

Thanks,

Alan.

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Alan wrote:
> Hi All,
>
> This is just an 'out of interest' type question.
>
> I connect to our SBS 2003 Premium server using a VPN connection, from
> a Win XP Home client
>
> If I click on the connection icon in the task bar, and select the
> 'details' tab, it lists the 'Server IP Address' as 10.0.0.XX (where XX
> is greater than 10).
>
> However, the actual server I am connecting to has an IP in the range
> (10.0.0.1 to 10.0.0.9)
>
> What is going on there?
>

The VPN connection does not terminate on the server LAN IP address.
It is a PPP (Point-to-Point Protocol) link which is a tiny network with
two nodes. Both nodes are assigned by SBS from its pool of VPN
addresses. While the link is up, both the SBS and the remote computer
have an additional network interface, and routing between this
interface and others can be controlled. That is why the main network
interface (and any others, for that matter) of a client computer must be
in a different subnet to the SBS, so the client computer knows which
interface (main or VPN) to send messages to.

It's possible to make the VPN pool of addresses whatever you like, so
that they are not in the same subnet as the SBS LAN. You would do this
if you wanted to isolate the VPN link from the LAN, so only the server
itself was accessible over the link.

"Joe" <> wrote in message
news:dv4apd$oug$1$...
> Alan wrote:
>> Hi All,
>>
>> This is just an 'out of interest' type question.
>>
>> I connect to our SBS 2003 Premium server using a VPN connection,
>> from a Win XP Home client
>>
>> If I click on the connection icon in the task bar, and select the
>> 'details' tab, it lists the 'Server IP Address' as 10.0.0.XX (where
>> XX is greater than 10).
>>
>> However, the actual server I am connecting to has an IP in the
>> range (10.0.0.1 to 10.0.0.9)
>>
>> What is going on there?
>>
>
> The VPN connection does not terminate on the server LAN IP address.
> It is a PPP (Point-to-Point Protocol) link which is a tiny network
> with
> two nodes. Both nodes are assigned by SBS from its pool of VPN
> addresses. While the link is up, both the SBS and the remote
> computer
> have an additional network interface, and routing between this
> interface and others can be controlled. That is why the main network
> interface (and any others, for that matter) of a client computer
> must be
> in a different subnet to the SBS, so the client computer knows which
> interface (main or VPN) to send messages to.
>
> It's possible to make the VPN pool of addresses whatever you like,
> so
> that they are not in the same subnet as the SBS LAN. You would do
> this
> if you wanted to isolate the VPN link from the LAN, so only the
> server
> itself was accessible over the link.


Superb reply Joe - Thanks!


--

The views expressed are my own, and not those of my employer or anyone
else associated with me.

My current valid email address is:



This is valid as is. It is not munged, or altered at all.

It will be valid for AT LEAST one month from the date of this post.

If you are trying to contact me after that time,
it MAY still be valid, but may also have been
deactivated due to spam. If so, and you want
to contact me by email, try searching for a
more recent post by me to find my current
email address.

The following is a (probably!) totally unique
and meaningless string of characters that you
can use to find posts by me in a search engine:

ewygchvboocno43vb674b6nq46tvb