ntp and time sync

[Uncle Jim]

Hi,

On Thu, Jan 23, 2003 at 01:21:34PM -0600, Eric R. wrote:

> A while back, I asked for input on NTP.  I had to go away from that 
> task, but it has now returned.  At this point, I'm stuck and lost.  So....
> 
> Is anyone synching their network using ntp?  I have my ws  synched, (our 
> stratum 2?) I have a cron job entered that keeps it in sync.  My problem 
> is I can't get the other Lin boxes (stratum 3?) to sync from this one.

Yes, I keep a network in sync with ntp.  However, I don't have any RedHat 7.x
boxes.  My main stratum 2 time server is a RH-5.2, xntp3-5.93-14 box (if it
works, don't fix it).  I also configured a RH-8.0, ntp-4.1.1a-9 stratum 2
server just to check things out.  After a few minutes everything seemed to
sync up and have correct time with both servers.

The xntp3-5.93-14 stratum 2 server's /etc/ntp.conf file contains

   server  tock.usnogps.navy.mil   # Falcon AFB, Colorado
   server  ntp.cc.utexas.edu       # University of Texas at Austin, Austin TX
   server  tick.wustl.edu          # Washington University at St. Louis
   server  tick.usno.navy.mil      # U.S. Naval Observatory

The ntp-4.1.1a-9 stratum 2 server's /etc/ntp.conf file contains

   restrict default ignore

   restrict 207.188.139.0 mask 255.255.255.0 notrust nomodify notrap

   restrict 204.34.198.41 mask 255.255.255.255 nomodify notrap noquery
   server 204.34.198.41    # tock.usnogps.navy.mil
   restrict 129.116.206.10 mask 255.255.255.255 nomodify notrap noquery
   server 129.116.206.10   # ntp.cc.utexas.edu
   restrict 128.252.19.1 mask 255.255.255.255 nomodify notrap noquery
   server 128.252.19.1     # tick.wustl.edu
   restrict 192.5.41.40 mask 255.255.255.255 nomodify notrap noquery
   server 192.5.41.40      # tick.usno.navy.mil

The xntp3-5.93-14 stratum 3 client's /etc/ntp.conf file contains

   server 207.188.139.8    # Use enfield.gallup.net

The ntp-4.1.1a-9 stratum 3 client's /etc/ntp.conf file contains

   restrict 207.188.139.8 mask 255.255.255.255 nomodify notrap noquery
   server 207.188.139.8    # enfield.gallup.net

Before I start ntpd I like to get the clock set close to real time because
ntp can take forever to sync up if the clocks aren't pretty darned close.

  rdate -s 207.188.139.8

and then set the hardware clock so that you don't have to fiddle with this
at the next boot time.

  hwclock --systohc -u             # I like to keep things in UTC

I use ntpq in the interactive mode to check the status of the machine.  The
pe and as commands will give you the information you need.  But don't be in
a hurry, ntp takes quite a while to become happy.
-- 
Jim