Windows Server 2012 as NTP Server for Windows Server 2008R2 Domain Controller

Question

We have one domain with 3 Windows Server 2008R2 DC's. Our Edge router is configured to get the time from the internet, and was our timesource for the PDC emulator. But lately we have migrated our major routers to Cisco IOS15, and now the timeservice on the
PDCe is unable to fetch the time. This is a known bug, as you can read here:
http://social.technet.microsoft.com/Forums/ja-JP/b16de048-8642-4799-b85a-ad092e17dd47/windows-server-2012-ntp-version-compatibility
Now I've found out that Windows Server 2012 does sync with the router. That's our DirSync server, and is in the same VLAN as our DC's. So I thought: I'll set up the Windows Server 2012 as new timeserver, so our PDCe can sync with that server. (Compony
policy is that DC's don't talk to the internet). Everything seems alright.
I've set:
w32tm /config /manualpeerlist:<IP of router>,0x8 /syncfromflags:manual
w32tm /config /reliable:yes
Changed the registry with:
HKLM\SYSTEM\CC\SERVICES\W32TIME\TIMEPROVIDERS\NTPSERVER - Enabled:1
HKLM\SYSTEM\CC\SERVICES\W32TIME\Config - AnnounceFlags:A
And stopped and started the W32Time service. I can see that the Windows 2012 server is fetching the correct time, and checked with NBTSTAT -NA that it's listening on port 123.
But our PDCe doesn't sync. (also changed the config so it has the 2012 server as timesource). Get the EventID 47:
Time Provider NtpClient: No valid response has been received from manually configured peer <w2012server> after 8 attempts to contact it. This peer will be discarded as a time source and NtpClient will attempt to discover a new peer with this DNS
name. The error was: The peer is unreachable.
What more can I try?

Answer 1

It only shows me the 3 DC's:
DC04.domain.local *** PDC ***[[::1]:123]:
    ICMP: 0ms delay
    NTP: +0.0000000s offset from DC04.domain.local
        RefID: 'LOCL' [0x4C434F4C]
        Stratum: 1
DC03.domain.local[10.x.x.x:123]:
    ICMP: 0ms delay
    NTP: -0.0097028s offset from DC04.domain.local
        RefID: DC04.domain.local [10.x.x.x]
        Stratum: 2
DC05.domain.local[10.x.x.x:123]:
    ICMP: 0ms delay
    NTP: -0.0127883s offset from DC04.domain.local
        RefID: W8D-VW-DC04.domain.local [10.x.x.x]
        Stratum: 2
Warning:
Reverse name resolution is best effort. It may not be
correct since RefID field in time packets differs across
NTP implementations and may not be using IP addresses.