Fixing Win32 Error 0x000006B3 (RPC_S_NOT_LISTENING)

The error code 0x000006B3 translates to RPC_S_NOT_LISTENING. This error message indicates that the server-side program or service you’re trying to connect to is not listening for RPC connections on the endpoint specified in the binding string.

Understanding Inactive RPC Listening Endpoints:

• In RPC communication, servers listen for incoming client connections on specific network endpoints (combination of address and port).
• The RPC_S_NOT_LISTENING error occurs when the RPC system attempts to connect to the server on the specified endpoint, but the program or service is not actively listening for connections there.

Reasons Behind RPC_S_NOT_LISTENING:

There are a couple of reasons why you might encounter this error:

• Incorrect Endpoint Information: The binding string might be using an incorrect network address, port number, or protocol that doesn’t match the configuration of the program or service on the server.
• Inactive Service: The program or service you’re trying to connect to might not be running or might not be configured to listen for RPC connections on the specified endpoint.
• Server-Side Firewall Restrictions: In some cases, firewall rules on the server might be blocking incoming RPC connections on the specified endpoint.

Resolving RPC_S_NOT_LISTENING:

1. Verify Binding String Endpoint:

   • Double-check the network address, port number, and protocol specified in the binding string. Ensure they match the configuration of the program or service on the server.

2. Consult Program Documentation:

   • Refer to the documentation for the program or service you’re trying to access remotely. It should specify the correct endpoint information (address, port, and protocol) for RPC connections.

3. Software Vendor Support:

   • If you’re unsure about the correct endpoint information or encounter issues with the remote service configuration, consider reaching out to the software vendor’s support for the program or service you’re trying to access remotely. They can provide guidance on the appropriate endpoint configuration for RPC connections.

4. Check Service Status (if applicable):

   • If you have access to the remote system, try checking the status of the program or service you’re trying to connect to via RPC. Ensure it’s running and configured to listen for connections on the specified endpoint.

5. Review Firewall Rules (if applicable):

   • If you suspect firewall restrictions might be blocking the connection, check the firewall rules on the server to ensure they allow incoming RPC connections on the specified endpoint and protocol.

6. Verify Network Connectivity:

   • Perform basic network connectivity checks to ensure communication between your client machine and the server is functional. Tools like ping can help with this initial verification.

Additional Tips:

• Some RPC tools or libraries might offer features to help with endpoint discovery on the server. These tools can help identify the correct endpoint configuration for the program or service.
• If managing the server-side configuration, ensure that programs or services are configured to listen for RPC connections on the intended endpoint and that firewall rules don’t inadvertently block such communication.

By understanding the concept of RPC listening endpoints and the reasons behind the RPC_S_NOT_LISTENING error, you can identify the cause of the inactive listening state. Carefully verifying the binding string endpoint, consulting program documentation, contacting software vendor support, checking service status (if applicable), reviewing firewall rules (if applicable), verifying network connectivity, and ensuring proper server-side configuration are some recommended steps to address this error.