[ntp:questions] Peer vs. Server lines in NTP.CONF

Brown, Ken F. Ken.Brown at kbslp.com
Fri Jan 16 21:50:48 UTC 2009


Please bear with me...I've taken over the time services so am just
getting a handle on this...

(in other words...newbie alert :)

We have 4 time servers - 3 with a GPS-style acquisition devices that
communicate via the com port - and one with just NTP running on it...all
are running on Windows 2000 (apparently bitten really, really bad with
wildly drifting time...long, long ago)

The NTP version is 4.2.0b at 1.1436-mbg-o (from Meinberg)

The GPS devices are all working (and connecting with hyperterm when
watching the device) all 3 servers are getting time from the devices
(initially - basically, I had to do the manual leap second adjustment
which is what caused me to dig into this).

After NTP is restarted, and it may be a couple of hours or more...the
servers start picking each other as a 'better' time source.  For example
(from the Meinberg GUI monitor):
time2 (refid=GPS) Stratum=1
time3 (refid=time2) Stratum=2
time1 (refid=time3) Stratum=3
time4 (refid=time2) Stratum=2

They all have good 'reach' values (377).

I've seen the stratum's get higher and higher - to where the 4 time
servers actually end up with stratum numbers in the 8,9,10,11 ranges.

I found this by using the Meinberg monitoring software from my
workstation (with NTP installed - same NTP version) with NTP.CONF
containing 'server' statements to all 4 of those time servers...I check
it a couple of times a day and they are constantly changing "who" has
the best time (which is normal, from what I've been reading) but the
refid is changing, also.

I guess the question is:  Is that normal behavior (for peering)?  Or
should I just reconfigure so that rather than 'peer' statements they all
have 'server' statements pointing to each other (and not 'peer'
statements).

I hope that makes sense...

Thanks!





The NTP.CONF file for the 3 time servers (with GPS devices) have lines
similar to below (different com ports involved):

server 127.127.1.0                  #allow synchronization with local
clock
fudge  127.127.1.0  stratum 12 refid LOCAL

#  connected to COM1 - use  127.127.29.1
#  connected to COM2 - use  127.127.29.2
server 127.127.29.2 prefer
fudge  127.127.29.2 stratum 0 

#And then have the following 'peer' statements:

peer time.localdomain.com prefer iburst
peer time2.localdomain.com prefer iburst
peer time3.localdomain.com prefer iburst
Server time4.localdomain.com

#(and the peer line is commented out if it is itself - i.e. if this is
the ntp.conf file 
#from time2, then the time2 peer line is commented out)

#There are additional 'server' lines to internet time sources, like:

#server 69.25.27.172     #ntp1.connectiv.com 
server 129.6.15.29      #time-b.nist.gov 
server 129.6.15.28      #time-a.nist.gov 
#server 66.92.68.246     #time.keneli.org 
#server 209.51.161.238   #clock.nyc.he.net 

#And they are slightly different on all 3 'peer' servers (to hit
different internet time sources)





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