Cisco 9500 not sync with NTP server

[kalzigitovadil]

I am having issues with Cisco 9500 switches and WS 2016 with configured NTP , can sync to public NTP servers on the internet but cannot sync to my internal NTP server. The current NTP server is running a local clock and according to theory it should serve its own
time to NTP clients right? 

I know that WS have some issues with Cisco switches to be as NTP sever , The Cisco NTP client wants to synchronize with a full implementation of NTP on the server and will not synch to W32Time. 

Can someone tell me some Software to make my Windows Server 2016 as NTP Server but not using W32Time. I have tried Meinberg to make Windows as NTP server but it wont helped me.

NTP server is reachable.


show run | s ntp 


ntp server 172.16.2.185 prefer



show ntp a d


172.16.2.185 configured, ipv4, insane, invalid, unsynced, stratum 16
ref ID .TIME., time 00000000.00000000 (05:00:00.000 ATY Mon Jan 1 1900)
our mode client, peer mode unspec, our poll intvl 64, peer poll intvl 1024
root delay 0.00 msec, root disp 0.00, reach 0, sync dist 15937.55
delay 0.00 msec, offset 0.0000 msec, dispersion 15937.50, jitter 0.00 msec
precision 2**10, version 4
assoc id 46288, assoc name 172.16.2.185
assoc in packets 0, assoc out packets 79, assoc error packets 0
org time E778E681.3E354028 (15:57:05.243 ATY Mon Jan 23 2023)
rec time 00000000.00000000 (05:00:00.000 ATY Mon Jan 1 1900)
xmt time 00000000.00000000 (05:00:00.000 ATY Mon Jan 1 1900)
filtdelay = 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
filtoffset = 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
filterror = 16000.0 16000.0 16000.0 16000.0 16000.0 16000.0 16000.0 16000.0
minpoll = 6, maxpoll = 10

[kalzigitovadil]

@Peter Paluch @MHM Cisco World @Richard Burts  Could you please help me ? 

[Peter Paluch]

Hello,

From the output you have shared:

172.16.2.185 configured, ipv4, insane, invalid, unsynced, stratum 16

The NTP server 172.16.2.185 claims itself to be unusable. You need to make sure that the NTP server considers itself as a valid and usable source of time. Currently, it does not seem to be the case. Unfortunately, I don't have enough experience with Windows server platforms to suggest how to force a Windows NTP service to serve the local time - my apologies.

Best regards,
Peter

[Richard Burts]

It is good to know that your Cisco devices are successful in sync ntp to Public Internet time servers. I agree that there are issues about using Windows as NTP server and like @Peter Paluch I do not have enough experience with NTP on Windows to make any good suggestions. Perhaps using Internet time source is adequate?

[IP_Cartel]

Yea your windows box will have a high stratum.  You can change the stratum level on a windows box, but preferably just sync with a public NTP.

https://www.ceos3c.com/sysadmin/configure-ntp-server-windows-server-2016/

[Leo Laohoo]

Microsoft has their own "interpretation" to NTP have their own set of standards which does not align with IETF NTP standard.  

This has been the issue since "day 1" when people have been synchronizing routers and switches to Windows OS.  

It is better to synch your router to an internet source and then configure the Windows 2016 to synch to the Cisco router & switches.

[johnd2310 · Accepted solution]

Hi,

The Meinberg software on your Win 2016 server should work as an NTP server. Make sure the Win 2016 server itself is syncing to an upstream server. It seems your NTP server is not syncing to an  upstream sources and the switch is not accepting time from that server.

When installing the Meinberg  software you can specify the upstream servers and also  configure local server as last restore

Thanks

John

[MHM Cisco World]

debug ntp packets <<- please share output of this