Troubleshooting Remote Distribution Point Connection Failures: A Comprehensive Guide

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When configuring System Center Configuration Manager (SCCM) or setting up a Distribution Point (DP), encountering errors is not uncommon. One prevalent issue is the “Distribution Manager failed to connect to the distribution point” error. This error, often accompanied by the error code 0x800706BA in the distmgr.log file, indicates a breakdown in communication between the SCCM Distribution Manager and the remote distribution point.

This guide provides comprehensive troubleshooting steps to resolve remote distribution point connection failures, ensuring smooth content distribution within your SCCM environment.

Fix Failed to Connect to Remote Distribution Point¶

If your system is unable to establish a connection with the remote distribution point, systematically follow these solutions to diagnose and rectify the problem.

1] Disable Firewall¶

Firewalls are crucial for network security, but they can sometimes inadvertently block legitimate connections. In the context of SCCM and distribution points, the firewall on either the SCCM server or the distribution point server might be obstructing the necessary communication.

To test if the firewall is the culprit, temporarily disable the firewall on the distribution point server. If disabling the firewall resolves the connection issue, it confirms that the firewall is indeed interfering. In such cases, instead of permanently disabling the firewall (which is not recommended for security reasons), you should configure firewall exceptions to allow SCCM communication.

Specifically, ensure that the firewall allows inbound and outbound traffic on the ports and protocols required for SCCM distribution point communication. This typically includes:

• TCP port 135 for RPC Endpoint Mapper.
• Dynamic RPC ports (typically in the range of 49152-65535, but can be customized).
• TCP port 445 for SMB (Server Message Block) if file sharing is used for content distribution.
• HTTP port 80 and HTTPS port 443 if IIS is used for distribution point roles like HTTP or HTTPS distribution points.

Consult your firewall documentation for instructions on adding exceptions for specific ports and applications. Carefully configure these exceptions to maintain security while enabling SCCM functionality.

2] Install IIS 6 WMI Compatibility Server Role¶

The IIS 6 WMI Compatibility server role is a vital component within Internet Information Services (IIS). It provides backward compatibility for management scripts and applications that were originally designed for IIS 6.0. SCCM, particularly older versions or certain management tasks, might rely on these older interfaces. If this component is missing on the distribution point server, it can lead to connection failures.

To install the IIS 6 WMI Compatibility role, follow these steps:

1. Open Server Manager: Access Server Manager from the Windows Start Menu or Server Manager icon on the taskbar.
2. Add Roles and Features: In Server Manager, click on Manage in the top right corner, and then select Add Roles and Features. This will launch the Add Roles and Features Wizard.
3. Installation Type: On the “Before you begin” page, click Next. Select Role-based or feature-based installation on the “Select installation type” page and click Next.
4. Server Selection: Choose Select a server from the server pool and select the target distribution point server from the list. Click Next.
5. Server Roles: In the “Server Roles” tab, locate and expand Web Server (IIS). Then expand Management Tools underneath it.
6. Select IIS 6 Management Compatibility: Within Management Tools, check the box next to IIS 6 Management Compatibility.
7. Add Features (if prompted): If a pop-up appears asking to add required features for IIS 6 Management Compatibility, click Add Features.
8. Complete Installation: Click Next through the remaining pages of the wizard and finally click Install on the “Confirm installation selections” page.
9. Verify Installation: Once the installation is complete, click Close.

After installing the IIS 6 WMI Compatibility role, restart the distribution point server and test the SCCM connection again to see if the issue is resolved.

3] Install IIS: Windows Authentication¶

Windows Authentication in IIS is a security feature that allows users to be authenticated using their existing Windows domain credentials. SCCM often leverages Windows Authentication for secure communication between site servers and distribution points. If Windows Authentication is not enabled in IIS on the distribution point server, authentication failures can occur, leading to connection problems.

To install and enable Windows Authentication in IIS:

1. Open Server Manager: Launch Server Manager as described in the previous section.
2. Add Roles and Features: Navigate to Manage > Add Roles and Features.
3. Installation Type and Server Selection: Follow steps 2-4 from the “Install IIS 6 WMI Compatibility Server Role” section to reach the “Server Roles” tab.
4. Select Windows Authentication: In the “Server Roles” tab, expand Web Server (IIS), then expand Web Server, and finally expand Security. Check the box next to Windows Authentication.
5. Complete Installation: Click Next through the remaining pages and click Install to begin the installation. Click Close once completed.
6. Restart IIS Service: After installation, restart the IIS service. You can do this by opening the Services application (search for “Services” in the Start Menu), locating “World Wide Web Publishing Service”, right-clicking on it, and selecting Restart.

With Windows Authentication installed and the IIS service restarted, re-attempt the connection from SCCM to the distribution point to check if the issue is resolved. Ensure that the IIS site used by the distribution point is configured to use Windows Authentication.

4] Parse an MOF File on the Target Server¶

MOF (Managed Object Format) files define the structure and classes of Windows Management Instrumentation (WMI). WMI is a core component of Windows for system management, and SCCM heavily relies on WMI to manage and monitor clients and distribution points. The smsdpprov.mof file is crucial for SCCM distribution point provider functionality. If this MOF file is corrupted or not properly registered, it can cause communication issues.

Parsing the MOF file using mofcomp.exe recompiles and registers the WMI classes defined in the file, potentially resolving issues related to WMI and SCCM distribution point communication.

Here’s how to parse the smsdpprov.mof file:

1. Locate smsdpprov.mof: The smsdpprov.mof file is typically located on the primary SCCM site server in the following directory: C:\Program Files (x86)\Microsoft Configuration Manager\bin\x64. However, the exact path may vary based on your SCCM installation.
2. Copy to Distribution Point Server: Copy the smsdpprov.mof file from the SCCM primary site server to a directory on the problematic distribution point server. For simplicity, you can copy it to C:\temp.
3. Open Command Prompt as Administrator: On the distribution point server, open Command Prompt with elevated privileges (Run as administrator).
4. Navigate to MOF File Location: In the Command Prompt, use the cd command to navigate to the directory where you copied the smsdpprov.mof file. For example, cd C:\temp.
5. Execute mofcomp.exe: Run the following command to parse the MOF file:
   

   mofcomp.exe smsdpprov.mof
   

6. Verify Success: After the command executes, you should see a message indicating “MOF file has been successfully parsed.”
7. Reboot Server: Reboot the distribution point server for the changes to fully take effect.

After rebooting, check if the connection issue with the SCCM distribution point is resolved.

5] Disable RPC Hardening¶

RPC (Remote Procedure Call) hardening is a security feature designed to enhance the security of RPC communication by mitigating potential vulnerabilities and attacks. While RPC hardening improves security, it can sometimes introduce compatibility issues with older applications or configurations, including SCCM distribution point connections. In certain scenarios, RPC hardening might become overly restrictive and block legitimate SCCM communication.

Disabling RPC hardening can be a troubleshooting step to determine if it is interfering with the distribution point connection. However, it’s crucial to understand that disabling RPC hardening can reduce security. Therefore, this should be considered a temporary diagnostic step and not a permanent solution in a production environment unless absolutely necessary and after careful risk assessment.

Before disabling RPC hardening, it is essential to back up your registry. This allows you to easily revert the changes if needed. To back up the registry:

1. Open Registry Editor: Type regedit in the Windows search bar and press Enter.
2. Export Registry: In Registry Editor, click on File > Export.
3. Save Backup: Choose a location to save the backup file, give it a descriptive name (e.g., “RPC_hardening_backup”), select “All” under Export range, and click Save.

Once you have backed up the registry, you can disable RPC hardening:

1. Open Registry Editor: Launch Registry Editor as described above.
2. Navigate to AppCompat Key: Navigate to the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole\AppCompat.
3. Check for RequireIntegrityActivationAuthenticationLevel: Look for a DWORD value named RequireIntegrityActivationAuthenticationLevel.
4. Create DWORD Value if Missing: If the RequireIntegrityActivationAuthenticationLevel DWORD value does not exist, you need to create it. Right-click in the right pane, select New > DWORD (32-bit) Value, and name it RequireIntegrityActivationAuthenticationLevel.
5. Set Value Data to 0: Double-click on the RequireIntegrityActivationAuthenticationLevel DWORD value. In the “Value data” field, enter 0 (zero). Ensure the “Base” is set to “Hexadecimal”. Click OK.
6. Close Registry Editor: Close the Registry Editor application.
7. Reboot Computer: Reboot the distribution point server for the changes to take effect.

After rebooting, test the connection to the SCCM distribution point. If disabling RPC hardening resolves the issue, consider if you can configure exceptions or less restrictive hardening settings instead of completely disabling it for long-term security. If disabling RPC hardening does not resolve the issue, you should revert the changes by importing the registry backup you created earlier. To import the backup, open Registry Editor, click File > Import, and select the backup file you saved.

How to Check SCCM Distribution Point Status?¶

Monitoring the status of your SCCM distribution points is essential for ensuring content is being distributed correctly and efficiently. SCCM provides built-in tools to check the status of distribution points and the content distributed to them.

To check the SCCM distribution point status:

1. Open Configuration Manager Console: Launch the SCCM console from your administrative tools.
2. Navigate to Monitoring Workspace: In the console, go to the Monitoring workspace at the bottom left.
3. Expand Distribution Status: In the Monitoring workspace, expand Distribution Status.
4. Select Content Status: Click on the Content Status node. This node displays the status of all content distributed in your SCCM environment.
5. View Content Distribution: To check the distribution status of a specific content item (like an application or package), right-click on the content item in the list and select View Content Distribution. This will show you the distribution status across all distribution points.

The Content Distribution view provides detailed information about the status of content on each distribution point, including:

• Success: Content is successfully distributed to the distribution point.
• In progress: Content distribution is currently in progress.
• Error: Content distribution failed to the distribution point.
• Waiting: Content distribution is waiting to start.

By regularly checking the content status, you can proactively identify and address distribution issues, including connection problems to distribution points.

What is Error Code 0x800706ba in SCCM?¶

The error code 0x800706ba, also known as RPC_S_SERVER_UNAVAILABLE, in SCCM indicates that the SCCM site server is unable to communicate with the client or distribution point over RPC (Remote Procedure Call) ports. This error essentially means that the server being contacted is not available or is not listening on the expected network ports.

In the context of SCCM distribution point connection failures, error 0x800706ba typically points to issues related to network connectivity or RPC communication between the SCCM site server and the distribution point server.

Common causes for error 0x800706ba in SCCM distribution point scenarios include:

• Firewall blocking RPC ports: As discussed earlier, firewalls on either the SCCM server or the distribution point server might be blocking the necessary RPC ports (port 135 and dynamic RPC ports).
• Network connectivity issues: Network problems such as network outages, DNS resolution failures, or routing issues can prevent communication between the servers.
• RPC service not running: The Remote Procedure Call (RPC) service or related services might not be running on the distribution point server.
• DCOM configuration issues: Distributed Component Object Model (DCOM) settings, which are related to RPC, might be misconfigured or restricted.
• RPC hardening: Overly restrictive RPC hardening settings can sometimes block legitimate SCCM communication.

When troubleshooting error 0x800706ba, focus on verifying network connectivity, firewall configurations, and the status of RPC-related services on both the SCCM site server and the distribution point server. The solutions outlined in this guide, such as checking firewall settings and disabling RPC hardening, directly address some of these common causes.

By systematically working through these troubleshooting steps, you can effectively diagnose and resolve remote distribution point connection failures in SCCM, ensuring the reliable and efficient delivery of content across your managed environment.

If you found these solutions helpful or have encountered other methods to resolve distribution point connection issues, please share your experiences in the comments below!