Unable to discover MID Server

[SamJoe]

Hi,

I tried discovering a MID server host (Windows Server) using the same MID running on it and I got a "Active, couldn't classify: No WMI connection" error.

However, I am able to discover the same MID server host using another MID server.

Has anyone come across this issue and how are you able to discover the MID server host using the same MID server?

Thanks

Sam

[Selva Arun]

Hi @SamJoe ,

The issue you are encountering, "Active, couldn't classify: No WMI connection," when trying to discover the MID server host using the same MID server, is a common challenge in ServiceNow Discovery. Below are the possible causes and solutions, along with supporting documentation to help you resolve the issue.

1. WMI Permissions Issue
   The MID server uses WMI (Windows Management Instrumentation) to classify and gather information about Windows hosts. If the MID server is running on the same host it is trying to discover, it may encounter permission or authentication issues.
   Solution: Ensure that the MID server service is running under a user account with sufficient permissions to access WMI on the local machine. The account should have administrative privileges on the host.
2. Localhost WMI Restrictions
   Some Windows configurations restrict WMI queries to the localhost, even if the user has administrative privileges.
   Solution: Check the local security policies or group policies on the Windows server. Ensure that WMI is not restricted for localhost queries. You can also test WMI connectivity locally using the wbemtest tool to confirm if WMI is accessible.
3. Firewall or Security Software Blocking WMI
   The Windows Firewall or third-party security software might block WMI traffic, even for local connections.
   Solution: Verify that the Windows Firewall allows WMI traffic. Specifically, ensure that the following ports are open:

• TCP 135 (for RPC)
• Dynamic RPC ports (range 49152–65535 by default)

If third-party security software is installed, check its settings to ensure it is not interfering with WMI.

1. MID Server Configuration
   The MID server might not be configured correctly to discover its own host.
   Solution: Check the config.xml file of the MID server (located in the MID server installation directory). Ensure that the mid.allow.localhost parameter is set to true. If this parameter is missing, add it manually:

<parameter name="mid.allow.localhost" value="true" /> 

Restart the MID server service after making this change.

1. ServiceNow Discovery Configuration
   The Discovery process might not be configured to allow the MID server to discover itself.
   Solution: In the ServiceNow instance, ensure that the Discovery schedule and credentials are correctly configured. Use the same credentials that work when discovering the host from another MID server.
2. Loopback Network Issues
   When the MID server tries to discover its own host, it may encounter issues with loopback network connections.
   Solution: Test the network connectivity to localhost or 127.0.0.1 from the MID server host. Ensure there are no restrictions or misconfigurations in the network settings.
3. Use Another MID Server
   If the above solutions do not resolve the issue, it may be simpler to use another MID server to discover the host. While it is possible to configure the MID server to discover itself, it is not always necessary or recommended.

Supporting Documentation and References

1. ServiceNow Community: No WMI Connection
   https://www.servicenow.com/community/itom-forum/no-wmi-connection/m-p/954684
2. ServiceNow Knowledge Base: Troubleshooting WMI Collector Issues
   https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0725165
3. ServiceNow Knowledge Base: MID Server Connectivity
   https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0780900
4. ServiceNow Community: WMI Credentials Fail on MID Server Host
   https://www.servicenow.com/community/itom-forum/wmi-credentials-fail-on-mid-server-host/td-p/957181
5. ServiceNow Community: Discovery and Firewall Configuration
   https://www.servicenow.com/community/itom-forum/about-discovery-windows-servers-from-mid-server-thro...
6. ServiceNow Knowledge Base: MID Server Troubleshooting
   https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0535180
7. ServiceNow Community: PowerShell and WMI Queries
   https://stackoverflow.com/questions/49695634/authentication-failed-using-windows-credentials-on-serv...

By following these steps and reviewing the documentation, you should be able to identify and resolve the issue. If the problem persists, it is often easier to use another MID server to discover the host. Let me know if you need further assistance.

If you believe the solution provided has adequately addressed your query, could you please **mark it as 'Helpful'** and **'Accept it as a Solution'**? This will help other community members who might have the same question find the answer more easily.

Thank you for your consideration.

Selva Arun

[SamJoe]

Thanks for the detailed suggestion Selva Arun. WMI and Network/Firewall cannot be an issue here as it is being discovered with other MID servers.

I will try changing the permission levels for the service account used for running the MID server service.

Thanks

Sam