The Microsoft Hyper-V connection uses Windows Management Instrumentation (WMI) and DCOM for client-server communication. Firewall policies may block this communication, causing an unsuccessful connection to the Hyper-V server.

The Hyper-V server listening port defaults to port 135 and then chooses a randomly configured port for further communication. If the firewall blocks WMI traffic or either of these two ports, communication with the server is unsuccessful. Administrators can modify the firewall policy to allow successful communication with the Hyper-V server.

Verify that all connection settings, including IP address, domain\username, and password are correct before performing the following firewall modifications.