Tag Archives: microsoft

Local and Domain NTP Overridden by Secure Time Service

Posted on by

Starting with Windows 10 1511, Microsoft introduced a new feature called Secure Time Seeding, part of the Secure Time Service (STS), as an upgrade to the W32TIME service. The STS uses information from SSL connections to validate NTP data. Information from this feature supersedes all other time sources, including locally configured NTP, domain controllers, and Hyper-V time synchronization.

I first noticed the feature when several of my Hyper-V virtual machines began shifting their system clocks backwards and forwards several times a minute. At first the time changes spanned a few hours, but as the machine uptime climbed, so did the time jumps. Eventually, the time was bouncing backwards and forwards by weeks, several times a minute. The Hyper-V time synchronization service was fighting with the new Secure Time Service and this wrecked havoc on authentication and any other services running on the systems.

Continue reading →

Unifi VPN Radius Challenge Fails with Invalid Password

Posted on by

An issue exists between the Ubiquiti Networks Unifi software controller v5.10.19 and a Microsoft Radius or Network Policy Server (NPS) when NTLMv2 responses are forced on all Domain Controllers. When this condition exists, radius calls from the Unifi controller fail with error event that indicates the password is invalid. The security logs on the radius server report the following failure:

Failure Information:
     Failure Reason:     Unknown user name or bad password.
     Status:             0xC000006D
     Sub Status:         0xC000006A     (Account logon with misspelled or bad password)

The issue is limited only to VPN connections. WiFi connections using the same Radius connection profile and user account succeed.

Applying the registry key in Microsoft KB 2811487 to the Radius server resolves the issue.

Set DWORD:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\RemoteAccess\Policy\Enable NTLMv2 Compatibility = 1