Miracast

Recently I had to troubleshoot a sticky Surface Hub Miracast Connection error for a customer. They were unable to connect to the surface hub from domain joined devices but a newly installed device from a blank Windows image was working as expected. I started Troubleshooting the Surface Hub Miracast Connection Error and checked all the points mentioned in the official Troubleshoot Miracast on Surface Hub post from Microsoft. Default Configuration # On a Windows 10 1709 device exists a default firewall rule to allow Miracast connections to wireless displays: But the connection attempt was still interrupted after a timeout. Looking trough Group Policy # After analyzing the Windows 10 Security Baseline Group Policy configuration I came across the following settings: Computer Configuration > Windows Settings > Security Settings > Windows Firewall with Advanced Security: In the settings for the public profile under the “Customize” section there’s a section called “Rule merging”: As you can see rule merging is turned of in the Windows 10 Security Baseline which means, **all locally configured firewall rules are being ignored for the public profile. **Because Miracast connections or connection attempts belong to the public profile of the Windows Firewall, the built-in local firewall rule gets always bypassed.