NTP Server is not Syncing with Cisco Switches

[jafrulla1986]

Dear Team,

I am facing NTP Synchronization issue.Cisco Switches are not Synchronized with NTP Server.

sh ntp status
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 119.2092 Hz, actual freq is 119.2088 Hz, precision is 2**18
reference time is DF549F3F.3BE61C39 (14:49:19.233 Kuwait Tue Sep 25 2018)
clock offset is 59.7548 msec, root delay is 633.32 msec
root dispersion is 207.40 msec, peer dispersion is 35.43 msec

sh ntp associations detail
192.168.1.6 configured, insane, invalid, unsynced, stratum 16
ref ID 0.0.0.0, time 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
our mode client, peer mode unspec, our poll intvl 64, peer poll intvl 64
root delay 0.00 msec, root disp 0.00, reach 0, sync dist 0.000
delay 0.00 msec, offset 0.0000 msec, dispersion 16000.00
precision 2**5, version 3
org time 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
rcv time 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
xmt time DF6827AB.CE4095A7 (10:24:27.805 Kuwait Wed Oct 10 2018)
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

[paul driver]

Hello

Can you ping the ntp server, is it reachable from the clients.

Are you using any authentication or access-lists

ip access extended 110
permit udp host <ntp server> any eq ntp
permit udp any host <ntp server>

debug ip packet detail 110
debug ntp packets

[jafrulla1986]

Hi Paul,

Please find the below debug Outputs.

Oct 10 09:04:35.824: NTP: xmit packet to 192.168.1.6:
.Oct 10 09:04:35.824: leap 3, mode 3, version 3, stratum 0, ppoll 64
.Oct 10 09:04:35.824: rtdel A221 (633.316), rtdsp 3519 (207.413), refid C0A80106 (192.168.1.6)
.Oct 10 09:04:35.824: ref DF549F3F.3BE61C39 (14:49:19.233 Kuwait Tue Sep 25 2018)
.Oct 10 09:04:35.824: org 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:35.824: rec 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:35.824: xmt DF683F23.D3152177 (12:04:35.824 Kuwait Wed Oct 10 2018)
.Oct 10 09:04:36.831: NTP: xmit packet to 192.168.1.6:
.Oct 10 09:04:36.831: leap 3, mode 3, version 3, stratum 0, ppoll 64
.Oct 10 09:04:36.831: rtdel A221 (633.316), rtdsp 3519 (207.413), refid C0A80106 (192.168.1.6)
.Oct 10 09:04:36.831: ref DF549F3F.3BE61C39 (14:49:19.233 Kuwait Tue Sep 25 2018)
.Oct 10 09:04:36.831: org 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:36.831: rec 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:36.831: xmt DF683F24.D4C15721 (12:04:36.831 Kuwait Wed Oct 10 2018)
.Oct 10 09:04:37.829: NTP: xmit packet to 192.168.1.6:
.Oct 10 09:04:37.829: leap 3, mode 3, version 3, stratum 0, ppoll 64
.Oct 10 09:04:37.829: rtdel A221 (633.316), rtdsp 3519 (207.413), refid C0A80106 (192.168.1.6)
.Oct 10 09:04:37.829: ref DF549F3F.3BE61C39 (14:49:19.233 Kuwait Tue Sep 25 2018)
.Oct 10 09:04:37.829: org 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:37.829: rec 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:37.829: xmt DF683F25.D44D71C8 (12:04:37.829 Kuwait Wed Oct 10 2018)
.Oct 10 09:04:38.835: NTP: xmit packet to 192.168.1.6:
.Oct 10 09:04:38.835: leap 3, mode 3, version 3, stratum 0, ppoll 64
.Oct 10 09:04:38.835: rtdel A221 (633.316), rtdsp 3519 (207.413), refid C0A80106 (192.168.1.6)
.Oct 10 09:04:38.835: ref DF549F3F.3BE61C39 (14:49:19.233 Kuwait Tue Sep 25 2018)
.Oct 10 09:04:38.835: org 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:38.835: rec 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:38.835: xmt DF683F26.D5EC2A8D (12:04:38.835 Kuwait Wed Oct 10 2018)
.Oct 10 09:04:39.825: NTP: xmit packet to 192.168.1.6:
.Oct 10 09:04:39.825: leap 3, mode 3, version 3, stratum 0, ppoll 64
.Oct 10 09:04:39.825: rtdel A221 (633.316), rtdsp 3519 (207.413), refid C0A80106 (192.168.1.6)
.Oct 10 09:04:39.825: ref DF549F3F.3BE61C39 (14:49:19.233 Kuwait Tue Sep 25 2018)
.Oct 10 09:04:39.825: org 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:39.825: rec 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:39.825: xmt DF683F27.D367EFBC (12:04:39.825 Kuwait Wed Oct 10 2018)
.Oct 10 09:04:40.823: NTP: xmit packet to 192.168.1.6:
.Oct 10 09:04:40.823: leap 3, mode 3, version 3, stratum 0, ppoll 64
.Oct 10 09:04:40.823: rtdel A221 (633.316), rtdsp 3519 (207.413), refid C0A80106 (192.168.1.6)
.Oct 10 09:04:40.823: ref DF549F3F.3BE61C39 (14:49:19.233 Kuwait Tue Sep 25 2018)
.Oct 10 09:04:40.823: org 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:40.823: rec 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:40.823: xmt DF683F28.D3D62E47 (12:04:40.827 Kuwait Wed Oct 10 2018)
.Oct 10 09:04:41.830: NTP: xmit packet to 192.168.1.6:
.Oct 10 09:04:41.830: leap 3, mode 3, version 3, stratum 0, ppoll 64
.Oct 10 09:04:41.830: rtdel A221 (633.316), rtdsp 3519 (207.413), refid C0A80106 (192.168.1.6)
.Oct 10 09:04:41.830: ref DF549F3F.3BE61C39 (14:49:19.233 Kuwait Tue Sep 25 2018)
.Oct 10 09:04:41.830: org 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:41.830: rec 00000000.00000000 (03:00:00.000 Kuwait Mon Jan 1 1900)
.Oct 10 09:04:41.830: xmt DF683F29.D4C4E430 (12:04:41.831 Kuwait Wed Oct 10 2018)

[Deepak Kumar]

Hi,

I can see "insane", It means:  The sanity checks have failed, so the time from the server is not accepted. The server is unsynced.

You can "debug ntp validity" and see which of the sanity checks is failing?

Best Tshoot guide for this issue is 

https://www.cisco.com/c/en/us/support/docs/ip/network-time-protocol-ntp/116161-trouble-ntp-00.html

Regards,

Deepak Kumar

[Leo Laohoo]

What is this NTP server? Is it a Microsoft-based machine?

[jafrulla1986]

Hi Leo,

Yes, Its Microsoft Based Machine.

[Leo Laohoo]

---

@jafrulla1986 wrote:

Yes, Its Microsoft Based Machine. 

---

It won't work because MS's implementation of "NTP" is incompatible with Cisco.

[jafrulla1986]

Hi Leo,

Could Please elaborate more on this. 

NTP sync was happening before when NTP server was 2008R2. Now we have upgraded NTP server to 2012R2.After that NTP Sync s not happening .

Do we have any other alternate solution to this issue?

[Leo Laohoo]

Do you have a router?

[jafrulla1986]

Yes , i have a router as well as L3 Switch also.