Linux – NTP configuration not recognized

linuxntpntpdredhat

I'm trying to configure NTP on my machine but it seems that the parameters I set are not being read by the system. Below is my /etc/ntp.conf file. (I applied the most basic configuration to eliminate other issues)

server 10.45.68.47
server 127.0.0.1

After I set the above configuration, I restart the ntpd process by doing the following:

service ntpd restart

And then I get the following output:

Shutting down ntpd:                                        [  OK  ]
ntpd: Synchronizing with time server:                      [FAILED]
Starting ntpd:                                             [  OK  ]

Moreover, I can see the following in /var/etc/messages:

 Apr  2 10:54:07 hsystem1a ntpd[21067]: ntpd exiting on signal 15
 Apr  2 10:54:07 hsystem1a ntpdate[21537]: can't find host ntpServer1 
 Apr  2 10:54:07 hsystem1a ntpdate[21537]: can't find host ntpServer2 
 Apr  2 10:54:07 hsystem1a ntpdate[21537]: no servers can be used, exiting

So it seems that the ntpServer1 and the ntpServer2 are being read from somewhere instead of the IPs I configured in /etc/ntp.conf.

NOTE: I done init 6 on the machine just in case.

UPDATE
It seems that the target server is reachable but it is not synchronized. I know that if the synchronization is successful, then "*" should appear near the server name:

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 omap            127.0.0.1        7 u   50   64  377    0.269  -21536.   4.813

Best Answer

On Red Hat there are a couple of things that happen when you do service ntpd restart.

  1. ntpd is stopped
  2. ntpdate is run to set an initial time. This is because, by default, ntpd will not adjust the system time past a certain threshold. ntpdate does a one off time set using a specified time server. You can do this manually with ntpdate 10.45.68.47 as long as ntpd isn't running.
  3. ntpd is started again

ntpd's servers are specified in /etc/ntp.conf but ntpdate takes them from a file called /etc/ntp/step-tickers. If you look in the ntpd script in /etc/init.d you'll notice that ntpdate uses this file if there is anything in it (if it is empty, the ntpdate step is skipped). You can put your time servers in here:

server 10.45.68.47

and ntpdate will use them to set the initial time.

As an aside, you shouldn't have localhost as a time server. Use a local server and maybe some servers from the ntp pool project. Make sure they are geographically close to you for best results. Also, I would re-instate the default Red Hat config as it has some sensible defaults i.e. not allowing other servers to set the time on your server.

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