Cisco NTP clock is unsychronised error

[LinuxAdmin]

Hello Experts,

I have recently configured NTP Server on my Cisco Router to point to a SuSE Server where chrony is running.

Here are the relevant Commands and their outputs:

router(config)#ntp server 1.5.XXX.22 prefer

router#show ntp conf
ntp server 1.5.XXX.22 prefer

router#show ntp information
Ntp Software Name : Cisco-ntpv4
Ntp Software Version : Cisco-ntpv4-1.0
Ntp Software Vendor : CISCO
Ntp System Type : Cisco IOS / 1RU

router#show ntp packets
Ntp In packets : 216704
Ntp Out packets : 217430
Ntp old version packets : 26162
Ntp protocol error packets : 0

router#sh ntp associations

address ref clock st when poll reach delay offset disp
~1.5.XXX.22 .INIT. 16 - 64 0 0.000 0.000 15937.
* sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured

router# show ntp associations detail
1.5.XXX.22 configured, ipv4, insane, invalid, unsynced, stratum 16
ref ID .INIT., time 00000000.00000000 (01:00:00.000 CET Mon Jan 1 1900)
our mode client, peer mode unspec, our poll intvl 1024, peer poll intvl 1024
root delay 0.00 msec, root disp 0.00, reach 0, sync dist 15947.14
delay 0.00 msec, offset 0.0000 msec, dispersion 15937.50, jitter 0.00 msec
precision 2**10, version 4
assoc id 4651, assoc name 1.5.XXX.22
assoc in packets 0, assoc out packets 15, assoc error packets 0
org time E6B6F3F7.845A1E18 (10:14:47.517 CEST Mon Aug 29 2022)
rec time 00000000.00000000 (01:00:00.000 CET Mon Jan 1 1900)
xmt time 00000000.00000000 (01:00:00.000 CET 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

router#show ntp status
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 250.0000 Hz, actual freq is 250.0117 Hz, precision is 2**10
ntp uptime is 1563557500 (1/100 of seconds), resolution is 4000
reference time is E6B2EFCE.849BA750 (09:07:58.518 CEST Fri Aug 26 2022)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 3937.51 msec, peer dispersion is 0.00 msec
loopfilter state is 'CTRL' (Normal Controlled Loop), drift is -0.000046991 s/s
system poll interval is 64, last update was 263864 sec ago.

As you can see , the clock is still unsychronised. The NTP Server (1.5.XXX.22) is from Router rechable. 

What could be the cause?

Thanx in advance.

[ammahend · Accepted solution]

Based on the output

“assoc in packets 0, assoc out packets 15” seems like router is trying but there is no response from server side. 

Are you sure there is no ntp authentication configured on chrony (ntp server) end ? Or firewall in between ?  If no auth or firewall configured then set the time manually on router close to reference clock give it few minutes this can help in synchronization , if it still doesn’t work then share output of debug ntp packet from router.

[LinuxAdmin]

There is no authentication. And the Router IP is allowed to query the time in NTP-Configuration files. 

router#clock set 12:35:00 29 August 2022
router#show clock
.12:35:04.417 CEST Mon Aug 29 2022

router#show ntp status
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 250.0000 Hz, actual freq is 250.0117 Hz, precision is 2**10
ntp uptime is 1564333300 (1/100 of seconds), resolution is 4000
reference time is E6B2EFCE.849BA750 (09:07:58.518 CEST Fri Aug 26 2022)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 4053.88 msec, peer dispersion is 0.00 msec
loopfilter state is 'CTRL' (Normal Controlled Loop), drift is -0.000046991 s/s
system poll interval is 64, last update was 271634 sec ago.

router#debug ntp packet
NTP packets debugging is on
router#

Do I have to execute any other commands to get the debug logs? I do not see anything.

[ammahend]

logging buffered debug

Logging buffered 64000

debug ntp packet 

After few minutes of running debug “show log”

Undebug all - to disable debug.

second option is if you just want to display debug logs on terminal then just use “term mon” command. 

[LinuxAdmin]

 NTP Configuration on UNIX Server is modified to allow the subnet on which NTP Server is configured on the router. And then it started working. Thanks  ammahend for pointing out the possibility.

[ammahend]

You are welcome