Ntp Service Does not Synchronise with Time Server

(Doc ID 2292949.1)

Last updated on AUGUST 23, 2017

Applies to:

Linux OS - Version Oracle Linux 5.0 and later
Linux x86-64
Linux x86

Symptoms

After adding new NTP servers into the file /etc/ntp.conf, the client server is not getting the correct time from NTP servers and NTP is being syncing to LOCAL machine rather than remote server.

1) Checking with ntpstat it seems being synchronised

root@server1 ~]# ntpstat
synchronised to local net at stratum 11
time correct to within 11 ms
polling server every 64 s

2) Also the NTP server is reachable and it's responding to the ntpdate client queries; so there are not network/firewall issues between both servers :

root@server1 ~]# ntpdate -q ntp-server1.ntpserver.com
server 10.1.9.56, stratum 4, offset 4.483660, delay 0.02567
19 Jul 14:27:13 ntpdate[322377]: step time server 10.1.9.56 offset 4.483660 sec

3) Running the ntpq monitoring daemon, it shows in the list of the known remote peers, there we can see  that it trusted the local machine (*LOCAL(0)) instead of remote NTP servers

root@server1 ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
=====================================================
*LOCAL(0) .LOCL. 10 l 14 64 377 0.000 0.000 0.000 <======================== Local machine is used as primary ntp server.
ntp-server1 .INIT. 16 u - 1024 0 0.000 0.000 0.000
ntp0 .INIT. 16 u - 1024 0 0.000 0.000 0.000
.

4) It's also being shown on NTP query

root@server1 ~]# ntpdc -c sysinfo
system peer: LOCAL(0) <======================== synchronised to LOCAL
system peer mode: client
leap indicator: 00
stratum: 11
precision: -24
root distance: 0.00000 s
root dispersion: 0.01122 s
reference ID: [127.127.1.0]
reference time: dd1cadc5.8408b723 Fri, Jul 21 2017 10:43:49.515
system flags: auth monitor ntp stats
jitter: 0.000000 s
stability: 0.000 ppm
broadcastdelay: 0.000000 s
authdelay: 0.000000 s

5) Finally the NTP servers have the stratum status in "16".  It means clients could not reach NTP server, even if they were tested with "ntpdate -q" and there is not other network issue.

root@server1 ~] ntpq -nc peers
remote refid st t when poll reach delay offset jitter
==============================================================================
*127.127.1.0 .LOCL. 10 l 39 64 377 0.000 0.000 0.000
10.1.9.56 .INIT. 16 u - 1024 0 0.000 0.000 0.000 <============= stratum 16

10.1.9.55 .INIT. 16 u - 1024 0 0.000 0.000 0.000 <============= stratum 16

 

Changes

New NTP client configuration or adding new NTP servers.

Cause

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