[ntp:questions] ntp multicast mode

Richard B. Gilbert rgilbert88 at comcast.net
Thu Dec 2 13:16:55 UTC 2010

On 12/1/2010 10:49 PM, Atul Gupta wrote:
> Hi all,
> My ntp client is taking some time before syncing up with the server in
> multicast mode, generally its waiting for 4 packets from server before
> syncing its time, is it normal , and if so , what is the reason for this.

NTPD is measuring the rate at which your clock ticks.  It does not 
*just* set the clock, it also attempts to make the clock tick at a rate 
of exactly one tick per second!

You can speed things up a *little* by using the "iburst" keyword in 
NTP.CONF.  NTPD can take as long as ten hours to achieve the accuracy of 
which it is capable.

If possible, you should let NTPD run twenty-four hours a day, seven days 
a week!

> Can i change this to 1 i.e. sync up on the first packet of ntp server?
You can start NTPD with the -g option which causes it to set the best 
possible approximation to the correct time.  NTPD *still* must determine
and correct, if necessary, the rate at which your clock ticks!

Given that computers frequently use quartz crystals that were rejected 
by quality control at the wrist watch makers, you should not put too 
much faith in an undisciplined clock!

> Please help!!
> Regards,
> Atul.

More information about the questions mailing list