Win 2012 R2 and NTP over IPv6

[Gert Doering]

Hi,

one of my colleagues just brought up a windows / ipv6 issue that I cannot
answer (and google just returns "disable ipv6!" as the top#1 link...) -
specifically, his server 2012 r2 is unable to sync to an IPv6-enabled
NTP server.

I can see queries and responses:

10:26:22.401681 IP6 2001:608:x:xx::zz.123 > 2001:608:0:c::123.123: NTPv3, Client, length 48
10:26:22.402150 IP6 2001:608:0:c::123.123 > 2001:608:x:xx::zz.123: NTPv3, Server, length 48

IPv6 connectivity is working fine - when pinging ntp.space.net, the server
will happily acknowledge receipt of the echo replies.

Windows firewall is disabled (box is behind ACLs and the ACLs permit NTP), 
so it really should be able to synchronize fine - but it doesn't.

So, before entering lenghty debug sessions, I'm hoping to hear from someone
that this is a known issue, and all you need to do is "X" (or "it is known
to not-work")...

Gert Doering
        -- NetMaster
-- 
have you enabled IPv6 on something today...?

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