Troubleshooting "No such host is known" error

Learn how to troubleshoot connectivity between OneIQ Pulse and VMware® endpoints.

Alpha Team avatar
Written by Alpha Team
Updated over a week ago


You must have access to VMware vCenter.

You must have access to Windows Server where OneIQ Pulse is installed.


The error message "No such host is known" in the context of VMware indicates that the system is unable to resolve the hostname or domain name specified for the VMware component or resource. This error typically occurs when there is a problem with DNS resolution or the specified hostname cannot be found in the DNS records.

If connectivity issues occur between OneIQ Pulse and a VMware endpoint, the following error is displayed upon clicking the Details button:


  1. Access the OneIQ Pulse Server: Initiate a session on the machine where OneIQ Pulse is installed.

  2. Run Diagnostic Command: Launch the Powershell terminal and execute the following command: Test-NetConnection -ComputerName <vCenter Hostname or IP Address> -Port <443>. Replace <vCenter Hostname or IP Address> with the actual hostname or IP address of your vCenter. Here are some examples:

    Test-NetConnection -ComputerName vcenter -Port 443 
    Test-NetConnection -ComputerName -Port 443
    Test-NetConnection -ComputerName -Port 443
  3. Analyze the Output: Review the results and compare them with the provided examples.

  4. Identify Connectivity Issues: If there’s a connectivity problem on port 443 between the OneIQ Pulse server and the VMware vCenter, proceed to the solution.

  5. Solution: Verify if the default VMware management API port (443) is in use, or if a custom one has been configured. For more details, refer to the article “Failed to connect to VMware management API”.

  6. Successful Connection: If the connection to the VMware vCenter management API is successful, no further action is required.

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