[ntp:questions] Sync issue

Greene, Rick rick.greene at ncogroup.com
Thu Sep 9 11:22:37 UTC 2010

Cancel this...turns out, our network team had forgot to put a route in for this subnet, as it was a new subnet of our Class B IP range.

All my testing was from a different subnet of the same Class B, but of course the internet time servers are in different subnets entirely.


-----Original Message-----
From: questions-bounces+rick.greene=ncogroup.com at lists.ntp.org [mailto:questions-bounces+rick.greene=ncogroup.com at lists.ntp.org] On Behalf Of Greene, Rick
Sent: Wednesday, September 08, 2010 11:20 AM
To: questions at lists.ntp.org
Subject: [ntp:questions] Sync issue

I'm working on setting up our own "master clock" servers for our organization to get NTP time synchronization from.

The design calls for our master clock servers to get their time from several public NTP servers.

I initially set this up using Fedora Core 13 running as a VMware server inside our network, and was able to get it to sync up properly:

     [root at coruxdev etc]# ntpq -p
          remote           refid      st t when poll reach   delay   offset  jitter
     +time-a.nist.gov .ACTS.           1 u   44 1024  377   13.884    2.153   7.738
     +clock.isc.org   .GPS.            1 u  815 1024  377   76.939   -6.417   0.171
     *time-b.nist.gov .ACTS.           1 u  937 1024  377   12.309    0.460   4.231

I then took that same config and built it on our DMZ VMware environment, and in spite of being assured that our firewall is allowing UDP 123, I can't get time sync to work:

      [root at extux66 ~]# ntpq -p
          remote           refid      st t when poll reach   delay   offset  jitter
      time-a.nist.gov .INIT.          16 u    - 1024    0    0.000    0.000   0.000
      clock.isc.org   .INIT.          16 u    - 1024    0    0.000    0.000   0.000
      time-b.nist.gov .INIT.          16 u    - 1024    0    0.000    0.000   0.000

I've tried several different NTP troubleshooting documents found on the web, none have helped.  I've turned off iptables that was running on the local server, that didn't make a difference.

What could possibly be causing this?


Rick Greene
Unix Support
NCO Group
507 Prudential Road
Horsham  PA  19044
office: 215-441-3529
   fax: 215-441-3886

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