Linux – Is the NTP configuration correct

linuxntp

I have a CentOS virtual machine running remotely, accessible via VPN. It was set up to sync time from two servers on the same network. The time set is approximately right, but seems to be drifting off. I am concerned by the mention of the date 2036 in output below, should I be?

/usr/sbin/ntpq -pcrv
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 10.245.8.100    10.249.8.100     2 u   24   64  377    1.185  12124.8  29.489
 10.249.8.100    .RMOT.          16 u    - 1024    0    0.000    0.000   0.000
assID=0 status=c011 sync_alarm, sync_unspec, 1 event, event_restart,
version="ntpd 4.2.2p1@1.1570-o Fri Nov 18 13:21:21 UTC 2011 (1)",
processor="x86_64", system="Linux/2.6.18-308.el5", leap=11, stratum=16,
precision=-20, rootdelay=0.000, rootdispersion=56.655, peer=0,
refid=INIT, reftime=00000000.00000000  Thu, Feb  7 2036  6:28:16.000,
poll=6, clock=d3fd6d1a.a01aab1b  Fri, Sep 14 2012  9:45:14.625, state=1,
offset=0.000, frequency=0.000, jitter=0.001, noise=0.001,
stability=0.000, tai=0

[edit] as per suggestions below, further information…

sudo /usr/sbin/ntpdate 10.245.8.100
14 Sep 13:02:02 ntpdate[7766]: step time server 10.245.8.100 offset 12.212849 sec

and ntp.conf

restrict 127.0.0.1 
restrict -6 ::1

server 10.245.8.100
server 10.249.8.100

driftfile /var/lib/ntp/drift

keys /etc/ntp/keys

server 10.245.8.100
restrict 10.245.8.100
server 10.249.8.100
restrict 10.249.8.100

Best Answer

Look weird.

  • "stratum=16" say it not synced to time source.
  • reach 377 - ntp server reachable.
  • offset 12124.8 - big out of sync

Attempt do "ntpdate 10.245.8.100" for quick sync clock at beginning.

Possible big adjustment disabled in configuration as measure against misconfiguration? Show your ntpd.conf

Add as first, restrict rule to allow synchronisation

# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery

# Permit all access over the loopback interface.  This could
# be tightened as well, but to do so would effect some of
# the administrative functions.
restrict 127.0.0.0 mask 255.0.0.0
restrict -6 ::1
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