NTP sync

[Suraj Kamble]

Hi, I am struggling with NTP sync for a lab. I have the below configuration

R1: NTP is synced with an authoritative server

R1#sh run | s ntp
ntp server 139.59.33.117

R1#sh ntp assoc

address ref clock st when poll reach delay offset disp
*~139.59.33.117 204.34.198.40 2 23 64 377 32.0 54201. 9123.2
* master (synced), # master (unsynced), + selected, - candidate, ~ configured

R1#sh ntp st
Clock is synchronized, stratum 3, reference is 139.59.33.117
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18
reference time is DCC95A47.870DC1AC (17:19:27.527 IST Fri May 19 2017)
clock offset is 98586.5516 msec, root delay is 292.59 msec
root dispersion is 112880.66 msec, peer dispersion is 14241.55 msec

-----------------------------------------------------direct link between R1(10.0.12.1) and R2(10.0.12.2)

I am using the same router R1 to forward time to another router. But the time is not getting synced. Is there any extra configuration to be done?

R2#sh run | s ntp
ntp server 10.0.12.1

R2#sh ntp assoc

address ref clock st when poll reach delay offset disp
~10.0.12.1 0.0.0.0 16 19 64 0 0.0 0.00 16000.
* master (synced), # master (unsynced), + selected, - candidate, ~ configured

R2#sh ntp st
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18
reference time is DCC9575D.7C3F74FB (17:07:01.485 IST Fri May 19 2017)
clock offset is -1569.5140 msec, root delay is 8.41 msec
root dispersion is 1685.71 msec, peer dispersion is 116.17 msec

.May 19 11:52:22: NTP: rcv packet from 10.0.12.1 to 10.0.12.2 on FastEthernet1/0:
.May 19 11:52:22: leap 0, mode 1, version 3, stratum 3, ppoll 64
.May 19 11:52:22: rtdel 4889 (283.340), rtdsp 6E24F0 (110144.287), refid 8B3B2175 (139.59.33.117)
.May 19 11:52:22: ref DCC95AC7.8B2D4ED0 (17:21:35.543 IST Fri May 19 2017)
.May 19 11:52:22: org 00000000.00000000 (05:30:00.000 IST Mon Jan 1 1900)
.May 19 11:52:22: rec 00000000.00000000 (05:30:00.000 IST Mon Jan 1 1900)
.May 19 11:52:22: xmt DCC95AD5.7CCE0EE7 (17:21:49.487 IST Fri May 19 2017)
.May 19 11:52:22: inp DCC95AF6.211816F0 (17:22:22.129 IST Fri May 19 2017)

[Mark Malone]

hi some things to try

manually setting your clock to the right time on the router will help ntp sync, make it easier for it to sync up , if the local hardware clock is way off it can cause issues syncing ...clock set .......

also on r1 set ntp source interface and then point r2 ntp server to that ip address

you could reload router 2 if its a LAB  as well that can be the quickest way to get it to sync sometimes too, it sworked for me in the past after messing around with them trying to get them to sync

what device an ios version are you doing this on

EDIT: also check that both routers are running same ntp version wont hurt t have them running same ,check.......show ntp ass detail | i vers

then to set it just ntp version x

[johnd2310]

Hi,

What is the time on R2 and what is the NTP configuration on R2? Try the following: Delete the NTP config on R2, manually set the clock on R2 as close to the correct time as possible using the "clock set" privilege exec command, and then added the NTP config again.

Thanks

John