[German]Small addendum to a topic that has been left here for a few days. Microsoft has already confirmed a new problem with Windows Server 2025 in connection with Active Directory Domain Controllers (DC) on April 11, 2025. After restarting the server operating system, the DC is no longer accessible. This is probably due to incorrectly assigned Windows Firewall profiles after each restart.
Microsoft has posted the support article Domain controllers manage network traffic incorrectly after restarting in the Release Health status section of Windows Server 2025 under Known Issues on April 11, 2025.
Issues with DCs after restart
The support article states that Windows Server 2025 domain controllers (e.g. servers hosting the Active Directory domain controller role) may not manage network traffic correctly after a restart. As a result, Windows Server 2025 domain controllers may not be reachable in the domain network. Or the DCs are incorrectly reachable via ports and protocols that should otherwise be prevented by the domain firewall profile.
Incorrect firewall profile for the DC is the cause
Microsoft writes that this problem results from the fact that domain controllers (DCs) do not use a domain firewall profile when they are restarted. Instead, the default firewall profile is used. The immediate consequence is that applications or services running on the domain controller or on remote devices may fail or remain unreachable in the domain network.
Microsoft's developers are working on a solution and want to correct this at some point with an update. Affected administrators must perform the following workaround each time they restart Windows Server 2025, which works as a DC.
Workaround: Restart the network adapter
Microsoft has suggested a temporary workaround for those affected. Administrators can restore the expected behavior by restarting the network adapters. This can be done manually in various ways, e.g. with the following command via PowerShell:
Restart-NetAdapter *
The problem is that the error reoccurs each time the Windows Server 2025 acting as a domain controller is restarted. Microsoft suggests creating the workaround to restart the network adapters as a scheduled task that restarts the network adapter each time the domain controller is restarted.
This has been issue since Betas!
German readers told me, it has been an issue since ten years.