com, DCOM problems

microsoft.public.vb.com - Microsoft Visual Basic


com >> DCOM problems

by Michael Moreno » Tue, 13 Dec 2005 17:03:39 GMT

Good morning,

I (and all our in house DCOM experts) am having difficulties with
configuring DCOM.

What we try to achieve is simple : Excel uses a COM dll that talks to
the server and receives callbacks from the server.

What I have is the following:

Machine 1 : COM Server EXE A

Machine 2 : COM DLL B on machine 2
Excel (or one of our apps) on machine 2

PC 1 PC2
A <-------> B <-------> Excel

What happens is Exec can talk to B and B connects successfully to A but
A cannot callback B.

When doing the opposite:
PC 2 PC1
A <-------> B <-------> Excel

Everything hangs. Calls are frozen. We don't get a Permission or Access
is denied. It simply hangs!

We have tried with Windows XP and 2000. There is no firewall on the
machines.

Everything seems to be correctly registered since if we run everything
on either PC1 or PC2 it all works correctly.
I am connected on the two machines that belongs to the same domain as
an Admin.

We have tried tens of settings in DCOMCNFG with any success.

Could you recommend us any else to check or a change please?

Many thanks,
MM

--
Michael
----
http://michael.moreno.free.fr/
http://port.cogolin.free.fr/


Top

com >> DCOM problems

by Dmitriy Antonov » Thu, 15 Dec 2005 01:23:00 GMT






Please check this out, IMO, description is exactly, like in your case

http://support.microsoft.com/default.aspx?scid=kb ;en-us;255890

Also, I found from my own expirience, that if you make changes in DCOM
settings, it often requires you to reboot either server or client or both in
order for this changes to start working. If you make changes and don't
reboot (most of the time it is the server to be rebooted), then you may miss
appropriate settings.

Dmitriy.




Top

com >> DCOM problems

by Tony Proctor » Thu, 15 Dec 2005 01:33:33 GMT

Any event-log entries Michael?

Tony Proctor






Top

DCOM problems

by Michael Moreno » Sun, 18 Dec 2005 18:08:29 GMT

Well.... A reboot did help!!!

Thanks.

--

----------------------------------------------

http://michael.moreno.free.fr/



Top
Similar Threads

1. DCOM Problem

2. DCOM problem after winxp SP2 

Dear All
I'm using VB6 and developed a Client/server application built on DCOM using 
callbacks, the problem is after installing the Win XP sp2 the program 
stopped working even after using the Firewall Object for adding my 
applications to the exceptions list and adding ports 135TCP 888TCP and 
1043TCP to the exceptions list and enabled the remote access, changed the 
Launch permissions in the dcomcnfg to allow everyone, it is still not 
working.
I tried using the CoInitializeSecurity API in both client and server, but no 
use!

Even when I try to run msinfo32.exe to monitor Remote computer ( Server ) it 
is not working too..

please tell me how to  do the following by code only so I can make a 
user-friendly packaging for my program:
    - authenticate my Class for Launching for everyone permission.
    - configure the firewall to enable my program to pass through.
    - do all the necessary tasks to enable my program to work by code.

Note: My program was fully running all functions in a client/server 
computers before updating with SP2.

Regards

3. Weird DCOM problem in XP SP2

4. DCOM Problems 

Hi,

Anyone had this type of problem:

Built a DCOM server using VB6 and clients using VB6. Depolyed server in W2K
server and using NT client.

When running client, can createobject OK but only with late binding (e.g.
set O = createobject([Class],[Server])), but crashes with error 458 "uses an
automation type not used in VB" when early bound (e.g. set oClass =
createobject(...)). Also crashes with create object to Object type and then
assign to class type (e.g. set O = createobject(): set oClass = O)

This works on some PCs and not others and I can't figure out why it doesn't
work.

Any help appreciated...

Neil

5. VB6: Odd DCOM problem - Visual Basic/VB

6. Odd DCOM problem 

"Maury Markowitz" < XXXX@XXXXX.COM > wrote in
message news: XXXX@XXXXX.COM ...
> The setup:
>
> I have a DLL library I need to call from Access clients around our
network.
>
> I created a small "stub" ActiveX EXE program with the Start Mode set to
> "ActiveX Component" and "Remote Server Files" turned on. The program
contains
> a single object, "Proxy", which has a single function inside, which has a
> single line of code. All it does it take the inputs passed to it through
DCOM
> and immediately call the DLL on that machine.
>
> On the client side in Access, VBA creates two variant arrays, calls
> CreateObject to make an instance of the object on the server machine, and
> then calls the function. In order to ensure that both the client and the
> server have the same version and registry info,  just before calling
> CreateObject I first run the stub application locally. One of the
> side-effects of running a DCOM VB application is that it registers itself,
> which is kind of nice.
>
> The problem:
>
> All of this code has been working fine for well over a year. Two weeks ago
I
> did something wrong, no idea what, and re-complied the stub and broke
> compatibility. I don't know how this happened, as the code literally
consists
> of three lines (include Function/End Function!). Ok, whatever.
>
> Now when I call the stub from the client application my machine, a dialog
> appears on the server saying that the runtime has exited incorrectly.
>
> However, when I run the client application on another machine, right
beside
> mine, it works fine.
>
> I have explored this more widely, and it appears that about 1/2 of the
> machines in the office continue to work fine, and the other half don't.
Yes,
> this is using the exact same client and server, I run them off the network
to
> be sure.
>
> Can anyone think of a reason for this? I assume that it has something to
do
> with the function signatures on the client machines being different than
the
> server, but if that is the case why does it work on any of them? And to
test
> this possibility I removed all related keys from my registry and re-ran
the
> stub, and this did not fix the problem.
>
> Maury
>

There are various tools you might use to track down the exact cause - but
you broke compatibility. Capture the original components to your development
box, and rebuild it repairing the problem. OR create a new component.

-ralph

7. DCOM Proxy Error - R/3 DCOM Connector Object Builder

8. how to allow a dcom client to change a registry value on the dcom 

Hi everyone,
Im dealing with the problem that a dcom client program should register 
itself on a different pc in the network, on which the dcom server program 
runs but cannot change registry values unless the user on the client pc 
belongs to the administrator group on the server.
Is there any way to change this behavior or a work around for this problem?
The background is like this: a user (who doesnt have administrative rights) 
starts a program on the client pc. This program connects itself  via dcom to 
the server and checks if for example enough licenses are left. In this 
progress it is necessary that a couple of values are changed in the registry.
Ive tried everything (IMHO) beginning with the rights for the dcom-object. 
Unfortunately nothing worked, except I added the user to the administrator 
group on the server pc which is of course not applicable.
Hope some of you can help me out on this problem.
Thanks for any answers in advance,
Thilo