2 Replies Latest reply on Oct 7, 2013 8:40 AM by 975148

    How much time difference allowable in ntpdate


      I gave the command ntpdate on 1 RHEL machine with reference to another RHEL machine like,


      ntpdate –b <machine 2>


      from machine 1 and time difference supposedly was less than 1 min between machine 1 and machine 2.


      But, I have got error like ‘ntpdate[5771] no server suitable for synchronization found’. This raises few queries like:


      1) How much time difference is allowable between 2 machines to sync? Is it that the difference should be less than 1 second?

      2) What are the pre-requisites to use the ntpdate command so that the operation can be performed smoothly.


      I hope, my question is clear.


      Please revert with the reply to my query.



        • 1. Re: How much time difference allowable in ntpdate

          1) The clocks must be within 600 seconds (10 minutes).  The idea is that you set the clock by your wristwatch to get "close enough" and then use ntpdate to actually set the time.


          2) Mostly, you must have connectivity from your client to the NTP server; firewalls opened for port 123; and the NTP server must be allowed to send time to the client and the client must be allowed to receive the time.  This is what all those nasty restrict lines in /etc/ntp.conf are for.

          1 person found this helpful
          • 2. Re: How much time difference allowable in ntpdate

            Thanks a lot for your answer.  I would a query for the first point as below:


            1) I have a query that I have not seen this figure of 600 seconds documented anywhere, please share the link or some other way so that I can get more insight into it.


            Request you to please revert.