Conference gyro::internet_toolss

4487.0. "Remote OLE through a firewall on NT/IIS???" by STKAI1::T_ANDERSSON (Tomas Andersson) Wed Feb 19 1997 11:34

    I'm currently involved in the development of an interactive
    route planning system, which runs under Microsoft Internet
    Information Server v2.0, on Windows NT v4.0. The system
    features a Visual Basic client DLL, running under OLEISAPI2,
    which is a standard ISAPI extension, and a Visual Basic OLE
    server, which is deployed on another NT machine. The client
    calls the server using remote OLE.
    
    We imagine that information basically flows as follows in our
    system:
    
    	User		Web user ->
    			Web browser ->
    			Our web page ->
    
    				Internet protocol
    
    	Web site	IIS ->
    	(NT I)		OLEISAPI2 ->
    			Query class in client DLL ->
    			Remote OLE stub on web machine ->
    
    				Remote OLE (some sort of RPC)
    
    	Server		Remote OLE stub on server ->
    	(NT II)		Agent class on OLE server ->
    			OLE server application (calculates reply) ->
    			Agent class on OLE server ->
    			Remote OLE stub on server ->
    
    			etc back to the user...
    
    The system described above works quite well in all respects,
    and we are now ready to position the web server outside the
    firewall (a Digital product). Can we do this without having
    to change the communication between client and server, i.e.
    can we simply move the client DLL to the real world web server,
    or do we need to specify a particular port that our application
    must use, or something like that? What other problems can we
    anticipate? We know very little about firewalls...
    
    Any insights will be of great value.
    
    Regards,
    
    - Tomas Andersson -

    I guess the answer to your question would be easier to determine if we
    could have a better understanding of how the Microsoft style OLE RPC
    communication works.  My (very limited) understanding is that this is a
    sort of LAN Manager (SMB) messaging protocol.  I don't know if this
    protocol can be layered or encapsulated on IP but that is essentially
    what would we necessary to get it through the Internet firewall.  
    
    If you can solve the above, the mechanism that you would use would be a
    TCP relay, and yes, there would be a requirement for a specific
    port/protocol mapping between your external client machine and internal
    server machine.
    
    /Chris/

>    route planning system, which runs under Microsoft Internet
>    Information Server v2.0, on Windows NT v4.0. The system

	I would expect you to upgrade this to 30 before you roll this out.
  IIS 3.0 comes on the SP2 service pack.

		Danny