Skip to content
vScope Support Page

RPC Server Is Unavailable (WMI)

When attempting to discover information with WMI, the error “RPC server is unavailable” may appear. This issue can stem from one of several common causes, which are outlined below with troubleshooting tips.

RPC Service Not Running

If the Remote Procedure Call (RPC) service is not running on the target servers, vScope cannot access WMI information.

Troubleshoot:

  • Check that the RPC service is running on the target servers. You can verify this by accessing the Services management console (services.msc) and ensuring that “Remote Procedure Call (RPC)” is listed as “Running.”

Name Resolution Issues

The RPC server’s hostname may be resolving to an incorrect IP address, which can lead vScope to attempt discovery on an IP that is not in use.

Troubleshoot:

  • Use the ping command to verify that the hostname resolves to the correct IP address.
  • Confirm that there are no DNS issues or incorrect entries in the host files.

Firewall or Security Software Blocking Traffic

Firewalls or security applications can block traffic on TCP port 135, which is used by RPC. Additionally, RPC may alternate on dynamic ports between TCP/UDP 49152-65535.

Troubleshoot:

  • First, confirm that TCP port 135 is open for outbound traffic from the vScope server.
  • Then, ensure that this port is open for inbound traffic on the target servers.
  • Check any dynamic port ranges (49152-65535) if needed.

Connectivity Issues

Network or connectivity issues may prevent vScope from accessing the target machine.

Troubleshoot:

  • Confirm the network connection between the vScope server and the target machine. Use network testing tools like ping or tracert to test accessibility.
  • Verify access and connectivity by following How to Confirm WinRM and Remote Scripting.

Additional Resources

By following these troubleshooting steps, you can identify and resolve the most common causes of the “RPC server is unavailable” error and restore WMI discovery functionality.