Overview

This article provides troubleshooting steps for the "The RPC server is unavailable" error encountered while adding a Windows Server Monitor or during data collection through WMI mode in Applications Manager.

This error indicates that Applications Manager cannot establish RPC/DCOM communication with the target Windows server. It is commonly caused by one or more of the following:

• Incorrect hostname or DNS resolution
• Windows Firewall or network firewall blocking RPC/WMI communication
• RPC, DCOM, or WMI services not running on the target server
• Required RPC dynamic ports are blocked
• Network connectivity issues between the Applications Manager server and the target server
• Incorrect DCOM or Windows Firewall configuration
  

Troubleshooting

Step 1: Verify the Server Name

Verify that the server is added using the appropriate name based on its environment:

• If the server is joined to a Domain: Use the Fully Qualified Domain Name (FQDN) or domain hostname.

• If the server is in a Workgroup: Use the local computer name.

• If the server is located in a DMZ or isolated network: Add the server's hostname and IP address to the following file on the Applications Manager server:

  C:\Windows\System32\drivers\etc\hosts
  

Also verify that the DNS record for the target server is correctly registered and resolves from the Applications Manager server.

Step 2: Verify Required Windows Services

Ensure that the following services are running on the target server:

• Remote Procedure Call (RPC)
• Windows Management Instrumentation (WMI)

To verify:

1. Open Run
2. Type services.msc
3. Verify that both services are in the Running state
4. Start the services if they are stopped

Step 3: Verify Firewall Configuration

Applications Manager establishes communication with remote Windows servers using DCOM over RPC. The connection process involves:

1. An initial connection through TCP port 135 (RPC Endpoint Mapper) on the target server
2. Subsequent communication through a dynamic RPC port (typically above 1024)

Required Firewall Configuration

To ensure successful WMI communication, configure the following:

• Open TCP port 135 (RPC Endpoint Mapper) on the target server
• Allow the required RPC dynamic port range through both Windows Firewall and any network firewall

Note: The default dynamic RPC port range varies by Windows Server version. For detailed information on the applicable port range for your environment, refer to: Secure Configuration - Windows Monitoring

To Restricting RPC Dynamic Port Range

For environments with strict firewall policies, configure Windows to use a restricted RPC port range (for example, 5000–5100).

Follow Microsoft's official guidance: Configure RPC Dynamic Port Allocation with Firewalls

Recommendation: Microsoft recommends configuring a minimum range of 100 RPC ports for production environments. Ensure the same port range is allowed in:

• Windows Firewall on the target server
• Any intermediate network firewalls between Applications Manager and the target server

Step 4: Enable Windows Firewall Rules

If Windows Firewall is enabled, ensure the required firewall rules are enabled.

Enable Remote Administration through Group Policy

1. Open Run
2. Execute:

   gpedit.msc
   

3. Navigate to:

   Computer Configuration → Administrative Templates → Network → Network Connections → Windows Firewall → Domain Profile
   

4. Enable the Remote Administration Exception policy

Step 5: Verify WMI Connectivity Using WBEMTEST

From the Applications Manager server:

1. Open Run
2. Execute:

   wbemtest
   

3. Click Connect
4. Connect using:

   \\<hostname>\root\cimv2
   

5. Enter the monitoring credentials under the Credentials tab
6. Click Connect
7. Observe the returned error code

Note:
If the connection succeeds using the IP address but fails using the hostname, verify:

• DNS resolution
• Entries in: C:\Windows\System32\drivers\etc\hosts

Remove any incorrect entries and retry using the hostname.

Step 6: Enable Windows Firewall Rules for RPC (0x800706BA)

If WBEMTEST returns 0x800706BA (The RPC Server is unavailable), execute the following commands on the target Windows server from an elevated Command Prompt:

netsh advfirewall firewall set rule group="Windows Remote Management" new enable=yes

netsh advfirewall firewall set rule group="Windows Management Instrumentation (WMI)" new enable=yes

netsh advfirewall firewall set rule group="Remote Administration" new enable=yes

If the last command returns:

No rules match the specified criteria

Then execute:

netsh firewall set service remoteadmin enable

After executing the above command, re-run the third command (Remote Administration) and repeat the WMI connectivity test (Step 5).

Contact Support

• Screenshot of the WBEMTEST error message
• Results of the WMI connectivity test using both the hostname and IP address
• Support Information File (SIF) generated after reproducing the issue