[ntp:questions] negative estbdelay?

Danny Mayer mayer at ntp.isc.org
Tue Oct 23 16:43:22 UTC 2007


Dave Johnson wrote:
> Just ran into a system that has a estbdelay of -2.6 seconds.  Needless
> to say this is causing the system to run 2.6 seconds behind, but at
> the right rate.
> 
> It is configured as a broadcastclient.  There is one stratum 1 system
> braodcasting on the subnet for which this client should sync to.
> 
> Something must have gone very wrong when this client tried to
> calculate the delay when it started up.
> 
> Should the system ever try to re-calibrate the broadcast delay once
> running or will it stay the same as long as the broadcaster keeps
> broadcasting?  Not even once a hour/day?
> 
> It seems very wrong to accept a negative broadcast delay, shoudn't
> ntpd check for this and try again or reject the peer?
> 
> Info below:
> 
> version is ntpq 4.2.4p3.
> 

If you are not using autokey authentication then it doesn't do the
autokey dance and as a result is unable to estimate the delay between
the broadcast client and the broadcast server. You didn't include the
client or server config file so it's hard to be sure.

Danny



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