Resolution
Directory and Resource Administrator 6.x
fact
Directory and Resource Administrator 7.x
symptom
DCOM errors appear in the System Event Log on the Directory and Resource Administrator (DRA) Server.
symptom
Error found in Microsoft Windows Application Event Log: ' DCOM was unable to communicate with the computer <computer_name> using any of the configured protocols.'
symptom
Error found in Microsoft Windows Application Event Log: 'This cache refresh process was unable to connect to the domain <computer_name.domain_name.com>. Possibly there are network configuration problems.'
cause
This is caused by an incorrect Distributed Component Object Model (DCOM) protocol setup on the remote server. As reflected in the Application Event Log above, the Directory and Resource Administrator (DRA) server received an error indicating the cache refresh failed when connecting to the specified computer due to network configuration problems. Other applications can also generate similar errors in the System Event Log.
fix
Verify and resolve any network configuration problems with the specified computer.
note
For more information on troubleshooting DCOM, see the following Microsoft webpage:
note
Understanding how this issue occurs:
- In Directory and Resource Administrator (DRA), Win32 calls are made to the operating system (OS) requesting a specific function be performed.
- The OS then performs the requested function using DCOM.
- Once the function is performed, the OS returns the results to DRA, which then logs an event in the Application log.
- If the OS cannot complete the requested function, it generates a DCOM error that is written to the System log.
- The error is also returned to DRA, which translates the error and writes it to the Application log.
- The time stamp on the DCOM entry in the System log will be slightly earlier, if not the same as, the DRA entry in the Application log.
note
What is DCOM?
Distributed component object model (DCOM) is an extension of Component Object Model (COM) technology. DCOM supports communication between objects on different computers on a network by handling low-level details of network protocols. This enables use of distributed programs consisting of multiple processes working together to accomplish a single task. First delivered in Windows NT 4.0, Service Pack 4, COM Internet Services (CIS) provides additional support that enables DCOM use over the Internet (using HTTP) when other protocols cannot be used due to a firewall on the server side or a proxy server on the client network.
To configure 32-bit COM and DCOM programs, you must use the Distributed COM Configuration Properties utility to set program properties, such as security and location. On the computer running the client application, you must specify the location of the server program that will be accessed or started. On the computer running the server application, you must specify the user accounts that will have permission to access or start the program.
The error that you are seeing is due the fact that you uninstalled the agent on the PDC using the SC command and DRA is still trying to access/use the agent. One of the agents functions is to direct users who are connecting to the User interface like the MMC to the DRA server. Without the agent installed on every DC, user connect to the MMC may not get directed to the DRA server and would receive an error stating that the DRA server cannot be found. Another function of the agents is to collect last logon statistics. If the agent is not installed on all DC, then you last logon stats may be inaccurate since any DC can authenticate a user.
Here are two Microsoft Knowledge Base articles which talk about DCOM and a similar issue. They are not this specific issue, however they are good references for DCOM information.
- http://support.microsoft.com/directory/article.asp?ID=KB;EN-US;Q290398
- http://support.microsoft.com/directory/article.asp?ID=KB;EN-US;Q176799