Accessing Exchange through site to site VPN with exchange on different gateway

Posted on 2006-04-28
Last Modified: 2010-03-18
We have recently setup a site to site VPN with 2 Cisco Pix firewalls.  The VPN connection works perfectly.  The problem we are running into is the the offsite users can't access their Exchange e-mail because the Exchange server is on a different gateway.  

Is there a way that we can keep the Exchange server on its own gateway but allow the remote users to access the Exchange e-mail through Outlook?
Question by:ATBChrisW
    LVL 7

    Expert Comment

    The answer is yes, but we need more information to help. In the pix point the route to the Exchange.
    LVL 104

    Expert Comment

    The only way I can think this is going to be possible is via some heavy modification of the route tables.
    You would have to put in a new route for the subnet of the other site to use the other gateway.

    Drop in to a command prompt and enter

    route /?

    to see the syntax and help for the route command.


    route print

    to see what the current routes are.


    Author Comment

    Ok let me lay this out a little.

    Let's say I my subnet for my main office is and my subnet for my new offsite location is  My default gateway for my exchange server is and the default gateway for all other machines using DHCP is


    Are you saying I may need to add a route to all the machines on the .20 subnet to the exchange gateway?

    LVL 104

    Accepted Solution

    You should be able to get away with the route command on the Exchange server only. It is so that Windows uses a different path to route the traffic from the Exchange server.


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