Re: NTP Clock Sync for Switch - CISCO Catalyst 2960-48TT - Page 3

JforJignesh · ‎12-08-2023

Hi,

Switch - CISCO Catalyst 2960-48TT - NTP time sync issue.

NTP server is Windows Server 2022 (Domain Controller).

Pls find below command output step by step for easy understanding.

CSA_SW#show clock detail
.19:28:40.268 IST Fri Dec 8 2023
Time source is NTP

CSA_SW#show ntp associations

address ref clock st when poll reach delay offset disp
~172.16.4.5 .LOCL. 1 74 1024 377 1.9 6638.9 24.9
* master (synced), # master (unsynced), + selected, - candidate, ~ configured

CSA_SW#ping 172.16.4.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.4.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms

CSA_SW#show ntp associations detail
172.16.4.5 configured, insane, invalid, stratum 1
ref ID .LOCL., time E91D9746.AF388DE6 (18:53:18.684 IST Fri Dec 8 2023)
our mode client, peer mode server, our poll intvl 1024, peer poll intvl 1024
root delay 0.00 msec, root disp 10019.42, reach 377, sync dist 10045.227
delay 1.86 msec, offset 6638.9188 msec, dispersion 24.87
precision 2**23, version 3
org time E91D9DD5.43307944 (19:21:17.262 IST Fri Dec 8 2023)
rcv time E91D9DCE.9FDD5878 (19:21:10.624 IST Fri Dec 8 2023)
xmt time E91D9DCE.9F624DC0 (19:21:10.622 IST Fri Dec 8 2023)
filtdelay = 1.86 2.33 1.75 1.68 1.68 1.91 1.62 1.80
filtoffset = 6638.92 6625.90 6613.31 6600.43 6587.45 6574.48 6561.85 6548.73
filterror = 0.02 15.64 31.27 46.89 62.52 78.14 93.77 109.39

CSA_SW#show ntp status
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 119.2092 Hz, actual freq is 119.2092 Hz, precision is 2**17
reference time is 00000000.00000000 (05:30:00.000 IST Mon Jan 1 1900)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.00 msec, peer dispersion is 0.00 msec

Logs as below

009084: .Dec 8 13:17:02.627: xmt E91D95CE.A0971F22 (18:47:02.627 IST Fri Dec 8 2023)
009085: .Dec 8 13:17:02.627: NTP: rcv packet from 172.16.4.5 to 172.16.5.151 on Vlan164:
009086: .Dec 8 13:17:02.627: leap 0, mode 4, version 3, stratum 1, ppoll 1024
009087: .Dec 8 13:17:02.627: rtdel 0000 (0.000), rtdsp AFEE7 (10995.712), refid 4C4F434C (76.79.67.76)
009088: .Dec 8 13:17:02.627: ref E91C45C6.A9DBAC63 (18:53:18.663 IST Thu Dec 7 2023)
009089: .Dec 8 13:17:02.627: org E91D95CE.A0971F22 (18:47:02.627 IST Fri Dec 8 2023)
009090: .Dec 8 13:17:02.627: rec E91D95D5.3DD2FA0D (18:47:09.241 IST Fri Dec 8 2023)
009091: .Dec 8 13:17:02.627: xmt E91D95D5.3DD3A1D3 (18:47:09.241 IST Fri Dec 8 2023)
009092: .Dec 8 13:17:02.627: inp E91D95CE.A10B1322 (18:47:02.629 IST Fri Dec 8 2023)
009093: .Dec 8 13:17:02.627: NTP: nlist 0, allow 0, found 0, low 0.000000, high 0.000000
009094: .Dec 8 13:17:02.627: NTP: no select intersection
009095: .Dec 8 13:17:02.627: NTP: no select intersection
009096: .Dec 8 13:34:06.624: NTP: xmit packet to 172.16.4.5:
009097: .Dec 8 13:34:06.624: leap 3, mode 3, version 3, stratum 0, ppoll 1024
009098: .Dec 8 13:34:06.624: rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)
009099: .Dec 8 13:34:06.624: ref 00000000.00000000 (05:30:00.000 IST Mon Jan 1 1900)
009100: .Dec 8 13:34:06.624: org E91D95D5.3DD3A1D3 (18:47:09.241 IST Fri Dec 8 2023)
009101: .Dec 8 13:34:06.624: rec E91D95CE.A10B1322 (18:47:02.629 IST Fri Dec 8 2023)
009102: .Dec 8 13:34:06.624: xmt E91D99CE.9FED5FEB (19:04:06.624 IST Fri Dec 8 2023)
009103: .Dec 8 13:34:06.624: NTP: rcv packet from 172.16.4.5 to 172.16.5.151 on Vlan164:
009104: .Dec 8 13:34:06.624: leap 0, mode 4, version 3, stratum 1, ppoll 1024
009105: .Dec 8 13:34:06.624: rtdel 0000 (0.000), rtdsp A01F0 (10007.568), refid 4C4F434C (76.79.67.76)
009106: .Dec 8 13:34:06.624: ref E91D9746.B0543BC1 (18:53:18.688 IST Fri Dec 8 2023)
009107: .Dec 8 13:34:06.624: org E91D99CE.9FED5FEB (19:04:06.624 IST Fri Dec 8 2023)
009108: .Dec 8 13:34:06.624: rec E91D99D5.4074AACC (19:04:13.251 IST Fri Dec 8 2023)
009109: .Dec 8 13:34:06.624: xmt E91D99D5.4075203D (19:04:13.251 IST Fri Dec 8 2023)
009110: .Dec 8 13:34:06.624: inp E91D99CE.A087061C (19:04:06.627 IST Fri Dec 8 2023)
009111: .Dec 8 13:34:06.624: NTP: nlist 0, allow 0, found 0, low 0.000000, high 0.000000
009112: .Dec 8 13:34:06.624: NTP: no select intersection
009113: .Dec 8 13:34:06.624: NTP: no select intersection
009114: .Dec 8 13:51:10.621: NTP: xmit packet to 172.16.4.5:
009115: .Dec 8 13:51:10.621: leap 3, mode 3, version 3, stratum 0, ppoll 1024
009116: .Dec 8 13:51:10.621: rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)
009117: .Dec 8 13:51:10.621: ref 00000000.00000000 (05:30:00.000 IST Mon Jan 1 1900)
009118: .Dec 8 13:51:10.621: org E91D99D5.4075203D (19:04:13.251 IST Fri Dec 8 2023)
009119: .Dec 8 13:51:10.621: rec E91D99CE.A087061C (19:04:06.627 IST Fri Dec 8 2023)
009120: .Dec 8 13:51:10.621: xmt E91D9DCE.9F624DC0 (19:21:10.622 IST Fri Dec 8 2023)
009121: .Dec 8 13:51:10.621: NTP: rcv packet from 172.16.4.5 to 172.16.5.151 on Vlan164:
009122: .Dec 8 13:51:10.621: leap 0, mode 4, version 3, stratum 1, ppoll 1024
009123: .Dec 8 13:51:10.621: rtdel 0000 (0.000), rtdsp A04F9 (10019.424), refid 4C4F434C (76.79.67.76)
009124: .Dec 8 13:51:10.621: ref E91D9746.AF388DE6 (18:53:18.684 IST Fri Dec 8 2023)
009125: .Dec 8 13:51:10.621: org E91D9DCE.9F624DC0 (19:21:10.622 IST Fri Dec 8 2023)
009126: .Dec 8 13:51:10.621: rec E91D9DD5.432F895A (19:21:17.262 IST Fri Dec 8 2023)
009127: .Dec 8 13:51:10.621: xmt E91D9DD5.43307944 (19:21:17.262 IST Fri Dec 8 2023)
009128: .Dec 8 13:51:10.621: inp E91D9DCE.9FDD5878 (19:21:10.624 IST Fri Dec 8 2023)
009129: .Dec 8 13:51:10.621: NTP: nlist 0, allow 0, found 0, low 0.000000, high 0.000000
009130: .Dec 8 13:51:10.621: NTP: no select intersection
009131: .Dec 8 13:51:10.621: NTP: no select intersection

Can anyone tell where I am doing wrong?

Thanx in advance.

Jignesh Patel

M02@rt37 · ‎12-11-2023

@JforJignesh

Possible to add wireshark on that server and see NTP requests from that Switch ?

Best regards
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JforJignesh · ‎12-13-2023

Data packet from Switch (NTP Client) to NTP Server

Frame 2464: 90 bytes on wire (720 bits), 90 bytes captured (720 bits) on interface \Device\NPF_{8174BFE7-7AC4-4F39-8B88-D4DD4EE73013}, id 0
Section number: 1
Interface id: 0 (\Device\NPF_{8174BFE7-7AC4-4F39-8B88-D4DD4EE73013})
Interface name: \Device\NPF_{8174BFE7-7AC4-4F39-8B88-D4DD4EE73013}
Interface description: CSA
Encapsulation type: Ethernet (1)
Arrival Time: Dec 13, 2023 14:00:02.727494000 India Standard Time
UTC Arrival Time: Dec 13, 2023 08:30:02.727494000 UTC
Epoch Arrival Time: 1702456202.727494000
[Time shift for this packet: 0.000000000 seconds]
[Time delta from previous captured frame: 0.118401000 seconds]
[Time delta from previous displayed frame: 0.118401000 seconds]
[Time since reference or first frame: 154.192968000 seconds]
Frame Number: 2464
Frame Length: 90 bytes (720 bits)
Capture Length: 90 bytes (720 bits)
[Frame is marked: False]
[Frame is ignored: False]
[Protocols in frame: eth:ethertype:ip:udp:ntp]
[Coloring Rule Name: UDP]
[Coloring Rule String: udp]
Ethernet II, Src: Cisco_f3:e9:c2 (00:1f:26:f3:e9:c2), Dst: VMware_4e:22:45 (00:0c:29:4e:22:45)
Destination: VMware_4e:22:45 (00:0c:29:4e:22:45)
Address: VMware_4e:22:45 (00:0c:29:4e:22:45)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Source: Cisco_f3:e9:c2 (00:1f:26:f3:e9:c2)
Address: Cisco_f3:e9:c2 (00:1f:26:f3:e9:c2)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
Internet Protocol Version 4, Src: 172.16.5.151, Dst: 172.16.4.5
0100 .... = Version: 4
.... 0101 = Header Length: 20 bytes (5)
Differentiated Services Field: 0xc0 (DSCP: CS6, ECN: Not-ECT)
1100 00.. = Differentiated Services Codepoint: Class Selector 6 (48)
.... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
Total Length: 76
Identification: 0x0000 (0)
000. .... = Flags: 0x0
0... .... = Reserved bit: Not set
.0.. .... = Don't fragment: Not set
..0. .... = More fragments: Not set
...0 0000 0000 0000 = Fragment Offset: 0
Time to Live: 255
Protocol: UDP (17)
Header Checksum: 0x5924 [validation disabled]
[Header checksum status: Unverified]
Source Address: 172.16.5.151
Destination Address: 172.16.4.5
User Datagram Protocol, Src Port: 123, Dst Port: 123
Source Port: 123
Destination Port: 123
Length: 56
Checksum: 0x2d08 [unverified]
[Checksum Status: Unverified]
[Stream index: 249]
[Timestamps]
[Time since first frame: 0.000000000 seconds]
[Time since previous frame: 0.000000000 seconds]
UDP payload (48 bytes)
Network Time Protocol (NTP Version 3, client)
Flags: 0xdb, Leap Indicator: unknown (clock unsynchronized), Version number: NTP Version 3, Mode: client
11.. .... = Leap Indicator: unknown (clock unsynchronized) (3)
..01 1... = Version number: NTP Version 3 (3)
.... .011 = Mode: client (3)
[Response In: 2465]
Peer Clock Stratum: unspecified or invalid (0)
Peer Polling Interval: 10 (1024 seconds)
Peer Clock Precision: -18 (0.000003815 seconds)
Root Delay: 0.000000 seconds
Root Dispersion: 1.000015 seconds
Reference ID: NULL
Reference Timestamp: NULL
Origin Timestamp: Dec 13, 2023 08:12:58.709025699 UTC
Receive Timestamp: Dec 13, 2023 08:12:49.292931920 UTC
Transmit Timestamp: Dec 13, 2023 08:29:53.297050497 UTC

Data packet from Switch NTP Server to Switch (NTP Client)

Frame 2465: 90 bytes on wire (720 bits), 90 bytes captured (720 bits) on interface \Device\NPF_{8174BFE7-7AC4-4F39-8B88-D4DD4EE73013}, id 0
Section number: 1
Interface id: 0 (\Device\NPF_{8174BFE7-7AC4-4F39-8B88-D4DD4EE73013})
Interface name: \Device\NPF_{8174BFE7-7AC4-4F39-8B88-D4DD4EE73013}
Interface description: CSA
Encapsulation type: Ethernet (1)
Arrival Time: Dec 13, 2023 14:00:02.727696000 India Standard Time
UTC Arrival Time: Dec 13, 2023 08:30:02.727696000 UTC
Epoch Arrival Time: 1702456202.727696000
[Time shift for this packet: 0.000000000 seconds]
[Time delta from previous captured frame: 0.000202000 seconds]
[Time delta from previous displayed frame: 0.000202000 seconds]
[Time since reference or first frame: 154.193170000 seconds]
Frame Number: 2465
Frame Length: 90 bytes (720 bits)
Capture Length: 90 bytes (720 bits)
[Frame is marked: False]
[Frame is ignored: False]
[Protocols in frame: eth:ethertype:ip:udp:ntp]
[Coloring Rule Name: UDP]
[Coloring Rule String: udp]
Ethernet II, Src: VMware_4e:22:45 (00:0c:29:4e:22:45), Dst: Cisco_f3:e9:c2 (00:1f:26:f3:e9:c2)
Destination: Cisco_f3:e9:c2 (00:1f:26:f3:e9:c2)
Address: Cisco_f3:e9:c2 (00:1f:26:f3:e9:c2)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Source: VMware_4e:22:45 (00:0c:29:4e:22:45)
Address: VMware_4e:22:45 (00:0c:29:4e:22:45)
.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
.... ...0 .... .... .... .... = IG bit: Individual address (unicast)
Type: IPv4 (0x0800)
Internet Protocol Version 4, Src: 172.16.4.5, Dst: 172.16.5.151
0100 .... = Version: 4
.... 0101 = Header Length: 20 bytes (5)
Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
0000 00.. = Differentiated Services Codepoint: Default (0)
.... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
Total Length: 76
Identification: 0x6354 (25428)
000. .... = Flags: 0x0
0... .... = Reserved bit: Not set
.0.. .... = Don't fragment: Not set
..0. .... = More fragments: Not set
...0 0000 0000 0000 = Fragment Offset: 0
Time to Live: 128
Protocol: UDP (17)
Header Checksum: 0x0000 [validation disabled]
[Header checksum status: Unverified]
Source Address: 172.16.4.5
Destination Address: 172.16.5.151
User Datagram Protocol, Src Port: 123, Dst Port: 123
Source Port: 123
Destination Port: 123
Length: 56
Checksum: 0x6206 [unverified]
[Checksum Status: Unverified]
[Stream index: 249]
[Timestamps]
[Time since first frame: 0.000202000 seconds]
[Time since previous frame: 0.000202000 seconds]
UDP payload (48 bytes)
Network Time Protocol (NTP Version 3, server)
Flags: 0x1c, Leap Indicator: no warning, Version number: NTP Version 3, Mode: server
00.. .... = Leap Indicator: no warning (0)
..01 1... = Version number: NTP Version 3 (3)
.... .100 = Mode: server (4)
[Request In: 2464]
[Delta Time: 0.000202000 seconds]
Peer Clock Stratum: primary reference (1)
Peer Polling Interval: 10 (1024 seconds)
Peer Clock Precision: -23 (0.000000119 seconds)
Root Delay: 0.000000 seconds
Root Dispersion: 10.158142 seconds
Reference ID: uncalibrated local clock
Reference Timestamp: Dec 13, 2023 04:42:19.102674899 UTC
Origin Timestamp: Dec 13, 2023 08:29:53.297050497 UTC
Receive Timestamp: Dec 13, 2023 08:30:02.727670599 UTC
Transmit Timestamp: Dec 13, 2023 08:30:02.727676299 UTC

M02@rt37 · ‎12-13-2023

Thanks @JforJignesh for that ouput.

Nothing to say at first seen.....

Best regards
.ı|ı.ı|ı. If This Helps, Please Rate .ı|ı.ı|ı.

Richard Burts · ‎12-13-2023

Thanks for the additional information. In looking at the trace output I notice these lines

Root Dispersion: 10.158142 seconds
Reference ID: uncalibrated local clock

I suspect that this root dispersion is what is preventing your Cisco from learning ntp time. I wonder if running debug for ntp might provide useful information?

HTH

Rick

JforJignesh · ‎12-14-2023

011705: .Dec 14 07:15:13.294: org E9252A01.4B77BDB4 (12:45:13.294 IST Thu Dec 14 2023)
011706: .Dec 14 07:15:13.294: rec E9252A0B.C21FF2E4 (12:45:23.758 IST Thu Dec 14 2023)
011707: .Dec 14 07:15:13.294: xmt E9252A0B.C2204D7D (12:45:23.758 IST Thu Dec 14 2023)
011708: .Dec 14 07:15:13.294: inp E9252A01.4BE603BB (12:45:13.296 IST Thu Dec 14 2023)
011709: .Dec 14 07:15:13.294: NTP: 172.16.4.5: offset 10.462665526, delay 0.00166, error 0.00002clock_filter(172.16.4.5, 10.462666, 0.00166, 0.00002)

011710: .Dec 14 07:15:13.294: NTP: nlist 0, allow 0, found 0, low 0.000000, high 0.000000
011711: .Dec 14 07:15:13.294: NTP: no select intersection
011712: .Dec 14 07:15:13.294: NTP: no select intersection
011713: .Dec 14 07:32:17.291: NTP: xmit packet to 172.16.4.5:
011714: .Dec 14 07:32:17.291: leap 3, mode 3, version 3, stratum 0, ppoll 1024
011715: .Dec 14 07:32:17.291: rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)
011716: .Dec 14 07:32:17.291: ref 00000000.00000000 (05:30:00.000 IST Mon Jan 1 1900)
011717: .Dec 14 07:32:17.291: org E9252A0B.C2204D7D (12:45:23.758 IST Thu Dec 14 2023)
011718: .Dec 14 07:32:17.291: rec E9252A01.4BE603BB (12:45:13.296 IST Thu Dec 14 2023)
011719: .Dec 14 07:32:17.291: xmt E9252E01.4AC98BA5 (13:02:17.292 IST Thu Dec 14 2023)
011720: .Dec 14 07:32:17.291: NTP: rcv packet from 172.16.4.5 to 172.16.5.151 on Vlan164:
011721: .Dec 14 07:32:17.291: leap 0, mode 4, version 3, stratum 1, ppoll 1024
011722: .Dec 14 07:32:17.291: rtdel 0000 (0.000), rtdsp A1E3E (10118.134), refid 4C4F434C (76.79.67.76)
011723: .Dec 14 07:32:17.291: ref E925062C.28D0D13E (10:12:20.159 IST Thu Dec 14 2023)
011724: .Dec 14 07:32:17.291: org E9252E01.4AC98BA5 (13:02:17.292 IST Thu Dec 14 2023)
011725: .Dec 14 07:32:17.291: rec E9252E0B.C4B7FE08 (13:02:27.768 IST Thu Dec 14 2023)
011726: .Dec 14 07:32:17.291: xmt E9252E0B.C4B85546 (13:02:27.768 IST Thu Dec 14 2023)
011727: .Dec 14 07:32:17.291: inp E9252E01.4B3CABD0 (13:02:17.293 IST Thu Dec 14 2023)
011728: .Dec 14 07:32:17.291: NTP: 172.16.4.5: offset 10.475418921, delay 0.00174, error 0.00002clock_filter(172.16.4.5, 10.475419, 0.00174, 0.00002)

011729: .Dec 14 07:32:17.291: NTP: nlist 0, allow 0, found 0, low 0.000000, high 0.000000
011730: .Dec 14 07:32:17.291: NTP: no select intersection
011731: .Dec 14 07:32:17.291: NTP: no select intersection
011732: .Dec 14 07:49:21.289: NTP: xmit packet to 172.16.4.5:
011733: .Dec 14 07:49:21.289: leap 3, mode 3, version 3, stratum 0, ppoll 1024
011734: .Dec 14 07:49:21.289: rtdel 0000 (0.000), rtdsp 10001 (1000.015), refid 00000000 (0.0.0.0)
011735: .Dec 14 07:49:21.289: ref 00000000.00000000 (05:30:00.000 IST Mon Jan 1 1900)
011736: .Dec 14 07:49:21.289: org E9252E0B.C4B85546 (13:02:27.768 IST Thu Dec 14 2023)
011737: .Dec 14 07:49:21.289: rec E9252E01.4B3CABD0 (13:02:17.293 IST Thu Dec 14 2023)
011738: .Dec 14 07:49:21.289: xmt E9253201.4A3E4C22 (13:19:21.290 IST Thu Dec 14 2023)
011739: .Dec 14 07:49:21.289: NTP: rcv packet from 172.16.4.5 to 172.16.5.151 on Vlan164:
011740: .Dec 14 07:49:21.289: leap 0, mode 4, version 3, stratum 1, ppoll 1024
011741: .Dec 14 07:49:21.289: rtdel 0000 (0.000), rtdsp A2147 (10129.990), refid 4C4F434C (76.79.67.76)
011742: .Dec 14 07:49:21.289: ref E925062C.277797E7 (10:12:20.154 IST Thu Dec 14 2023)
011743: .Dec 14 07:49:21.289: org E9253201.4A3E4C22 (13:19:21.290 IST Thu Dec 14 2023)
011744: .Dec 14 07:49:21.289: rec E925320B.C7774404 (13:19:31.779 IST Thu Dec 14 2023)
011745: .Dec 14 07:49:21.289: xmt E925320B.C777B975 (13:19:31.779 IST Thu Dec 14 2023)
011746: .Dec 14 07:49:21.289: inp E9253201.4AAC2A30 (13:19:21.291 IST Thu Dec 14 2023)
011747: .Dec 14 07:49:21.289: NTP: 172.16.4.5: offset 10.488315795, delay 0.00166, error 0.00002clock_filter(172.16.4.5, 10.488316, 0.00166, 0.00002)

011748: .Dec 14 07:49:21.289: NTP: nlist 0, allow 0, found 0, low 0.000000, high 0.000000
011749: .Dec 14 07:49:21.289: NTP: no select intersection
011750: .Dec 14 07:49:21.289: NTP: no select intersection

Richard Burts · ‎12-14-2023

Jignesh

Thanks for the output. Unfortunately it does not add anything that we did not already know. I continue to think that the root dispersion is part of the issue. Can you tell us anything about the windows device acting as ntp master? I know that in the past the version of ntp running on some windows devices was a simplified version of ntp (more like sntp) than a full implementation of ntp.

HTH

Rick

obi1987 · ‎05-16-2024

Are you able to solve it? I have the same problem.

Richard Burts · ‎05-16-2024

Unfortunately we do not know whether the OP resolved the problem or not. If you want us to help you with your issue then you need to provide information about your situation. Perhaps we can start with the output of these commands

show ntp status

show ntp associations detail

HTH

Rick

obi1987 · ‎05-21-2024

I have a windows 10 running with NTP server (10.16.3.130) and there are other pc sync with that NTP server. It is working fine. I have also one Hirschmann switch it is also able to sync to NTP server PC.

I have cisco 2960-CX which is not able to sync with NTP server.

Following are tge result from cisco switch

KBV4636-SWI112#sh ntp status
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 286.1023 Hz, actual freq is 286.1023 Hz, precision is 2**19
ntp uptime is 2200 (1/100 of seconds), resolution is 3496
reference time is 00000000.00000000 (01:00:00.000 UTC Mon Jan 1 1900)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.16 msec, peer dispersion is 0.00 msec
loopfilter state is 'FSET' (Drift set from file), drift is 0.000000000 s/s
system poll interval is 64, never updated.

-----------------------------

10.16.3.130 configured, ipv4, insane, invalid, stratum 2
ref ID 10.16.3.130 , time E9F6D205.25F17A2B (08:55:49.148 UTC Tue May 21 2024)
our mode client, peer mode server, our poll intvl 64, peer poll intvl 64
root delay 0.06 msec, root disp 13768.70, reach 3, sync dist 13836.85
delay 1.30 msec, offset 24.1289 msec, dispersion 62.94, jitter 4.44 msec
precision 2**23, version 4
assoc id 56228, assoc name 10.16.3.130
assoc in packets 7, assoc out packets 7, assoc error packets 0
org time 00000000.00000000 (01:00:00.000 UTC Mon Jan 1 1900)
rec time E9F6D4F2.C5F18797 (09:08:18.773 UTC Tue May 21 2024)
xmt time E9F6D4F2.C5F18797 (09:08:18.773 UTC Tue May 21 2024)
filtdelay = 1.30 1.95 2.90 1.86 1.68 2.60 4.75 0.00
filtoffset = 24.12 20.36 19.73 20.15 20.10 19.58 18.44 0.00
filterror = 0.00 0.87 0.90 0.93 0.96 0.99 1.02 16000.0
minpoll = 6, maxpoll = 10

---------

KBV4636-SWI112#sh ntp packets
Ntp In packets : 7
Ntp Out packets : 7
Ntp bad version packets : 7
Ntp protocol error packets : 0

Richard Burts · ‎05-21-2024

Thank you for the additional information. It is helpful to know that your ntp server is a windows machine. As I described in a previous post in this discussion, the version of NTP running on many Windows machines is not a full feature implementation of the protocol. I believe that this part of your output "10.16.3.130 configured, ipv4, insane, invalid, stratum 2" confirms this. It regards the server as "insane".

HTH

Rick

obi1987 · ‎05-22-2024

So, It means the switch will not able to sync with windows NTP server.

Leo Laohoo · ‎05-22-2024

Cisco routers & switches cannot synchronize to a Windows-based NTP server. This has been known for several decades now.

This is all because of Microsoft's "interpretation" of NTP protocol and does not see "eye-to-eye" with Cisco's.

For about US$100, a Raspberry Pi-based NTP server (Stratum 1) can be built.