VPN without Default Gateway

Posted on 2009-02-11
Last Modified: 2012-05-06
Okay. This is going to sound funny.
I have installed a vpn router for a client at their remote office.  I have PPTP VPN setup and working fine.
Problem is:  Client devices do not have a gateway setup.  They do have IP address and subnet mask, but no default gateway.
They are unable to access these devices through the VPN. But, when they are in the building and wired in, they can access the devices.
I've tried to explain to them, that tney MUST set a default gateway on these devices.
But, they are relunctant.
So, my question is:  Is it possible to route these devices to my PPTP VPN without the devices having a gateway address?
Question by:david_glidewell
    LVL 1

    Expert Comment

    Using route for adding a routing rule for only that  ip address / Route should work:

    start --> run --> cmd <enter>

    route -p ADD <destination> MASK <destination subnet> <gateway>

    the -p  switch makes the route persistent.

    or type route /?  for more information

    Author Comment

    The devices are NOT windows machines.

    They are manufacture control systems, monitor systems, etc.

    So, I can't just add route statements on the machines.

    I need to manage the solution from the router end. (if possible)
    LVL 10

    Expert Comment

    If they are on the VPN and have the actual ip address of the devices, there is no reason they could not connect. How are they attempting this? Do the devices have a Name they are trying to use?
    LVL 10

    Expert Comment

    If you could give a little more info on the devices. models?

    Author Comment

    This is a manufacturer environment.  They have various vendors and systems (alarm control unit, boiler monitors, chiller flow control, HVAC sensors, etc, etc).

    The vendors are given PPTP VPN access to the network to access their devices to manage them and help when troubleshooting issues as they arise.

    They devices are setup with a IP address, but no gateway. I don't understand why the vendors have recommended not setting gateways, but they is why the client is relunctant to setting gateways.

    Each Vendor has a username / password to the PPTP VPN.  The PPTP VPN assigns these users a static IP address on a non-existent network.  I have setup source route statements that allows each user/static ip to access only their partiucluar equipment.
    Network 10.10.132.x / 24
    PPTP VPN User (vendor 1):
    Source route:
    destination: gateway

    I am able to ping actual computers with gateways successfully, but the devices without gateways are not responding to pings.

    This is a more difficult router config, than I do on daily basis.  And, I never try to setup a situation why no default gateways are allowed. So, I'm in uncharted waters personally.

    I'm looking for advice, suggestions.

    This is a SnapGear VPN Router. Linux based router.
    I can program it to do anything that a Cisco Router can do. I just need suggestions.

    Is it possible to do this without default gateways setup on the devices.
    (by the way, i've used this type of config at medical offices / medical devices. But, they allowed default gateways in their devices, so everything just worked.)

    LVL 10

    Accepted Solution

    >Each Vendor has a username / password to the PPTP VPN.  The PPTP VPN assigns these users a static IP address on a non-existent network.  I have setup source route statements that allows each user/static ip to access only their partiucluar equipment.<

    The problem here is you're using a non-existent network, therefore it's most likely not going to work since the network that services the routing requests for the main network is not available. I forgot how to do it but in one of my linux classes years ago we setup routes through the ip tables that could translate everything properly. but we still granted access to the network resources. You may just want to request this question be closed and add linux/cisco networking rather than windows networking in the section. Since if the router runs linux and works like a cisco, you'll find all the guru's in those sections that know if it's possible to route that way.

    If it were me I'd just add the gateway to the devices and save the headache.

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