DCDiag reports “not advertising as time server”

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Just a quick post.

Was onsite recently and had a DC that was not advertising is a time server. DCDiag confirmed it.

Checked announceflags and it was set to 10 in hex (0x00000010) instead of 10 in decimal (0x0000000A).

Changed registry value and use “w32tm /config /update” and all was well. Interestingly it appears to only read last value. So even he (0x0000001A) also works and advertises as time server. Presumably because it reads the last character “A” and thinks

A = 10 = (0x8) + (0x2)

and as per https://technet.microsoft.com/en-us/library/cc773263(WS.10).aspx#w2k3tr_times_tools_uhlp 

AnnounceFlags
Registry path

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config

Version

Windows XP, Windows Vista, Windows Server 2003, and Windows Server 2008

This entry controls whether this computer is marked as a reliable time server. A computer is not marked as reliable unless it is also marked as a time server.

  • 0x00 Not a time server
  • 0x01 Always time server
  • 0x02 Automatic time server
  • 0x04 Always reliable time server
  • 0x08 Automatic reliable time server

The default value for domain members is 10. The default value for stand-alone clients and servers is 10.