[ntp:questions] Re: those secret incantations!!!

Richard B. Gilbert rgilbert88 at comcast.net
Tue Mar 8 01:25:01 UTC 2005

Charles wrote:

>Can anybody recommend a good on-line discussion or
>glossary or dictionary of the various terms used in the
>for fedora core 3 file /etc/ntp.conf  ???
>In particular, the word "fudge".
If you have the source code for the NTP Reference implementation, you'll 
find some explanation in the file notes.html.

In brief, fudge allows  you to specify two time values, two flags and/or 
two integral values to be applied to a particular clock or server.
The meanings/ functions of these values and flags are dependent on the 
drivers for the specific reference clocks.  See the source code for details.

The most common use of fudge is:

# Declare the local clock to be the clock of last resort.
# It will be used to serve time in the absence of any other.
server              # Local clock, unit 0
fudge stratum 10

in which fudge is used to adjust the stratum of the local clock to a 
value that will prevent all but the truly desparate from using it, 
should it ever be required to act as a time server.   This is useful in 
the case where you lose your network connection to the outside world and 
your local clock becomes unsynchronized..  The above statements allow 
ntpd to serve time using the local clock as a reference clock without 
any significant risk that anyone with access to a better clock will 
believe that your unsynchronized local clock is a desirable clock to 
synchronize with.

More information about the questions mailing list