Hi,
again I have to start a topic about a NTP Server and Client issue. It really drives me crazy because I have spent days to find the problem but I cannot get it working. There is a RB3011(192.168.0.254) which acts as a NTP Server in my local net 192.168.0.0/24. Here is the NTP server export(ROS 6.38.1):
/system ntp server
set broadcast=no broadcast-addresses="" enabled=yes manycast=yes multicast=no
/system ntp client
set enabled=yes mode=unicast primary-ntp=131.234.137.63 secondary-ntp=\
176.9.103.8
;;; NTP
chain=input action=accept protocol=udp dst-address=192.168.0.254
dst-port=123 log=no log-prefix=""
The NTP client on the NTP server shows as status “synchronized”. So for me it looks like the RB3011 has a valid time which he can provde to the clients.
My central HP1820-24G receives the NTP message like usual and updates his time as expected. In contrast all Mikrotik devices and a windows 7 machine do not get NTP updates… Here is the NTP Client script export from a client in the network (map2n with IP 192.168.0.190):
/system ntp client
set enabled=yes mode=unicast primary-ntp=192.168.0.254 secondary-ntp=192.168.0.254
As a side not I am using the NTP packge on ROS so there is no SNTP client active but instead the normal “NTP client”. All devices can ping each other and have internet access. It is a big pain for me to see such an “easy” feature not working. Can anybody help me?
[Update]
If is use the tool http://www.timesynctool.com/ for syncing my windows 7 machine it works without any problems. I did use an external time server. If I use the same time server inside the normal windows time sychronisation settings it cannot sync. 
[Update 2]
Even if I disable all firewall filter rules my machines are not able to connect to an external NTP server. So there is only one srcnat rule left and one rule to change the TCP MSS.
Regards Toby