Configure NTP - should be a snap, but it isn't

[Kevin O'Gorman]

On Fri, May 31, 2002 at 10:17:23PM -0400, Kurt Wall wrote:
> On Fri, 31 May 2002 17:26:36 -0700
> "Kevin O'Gorman" <kevin at kosmanor.com> wrote:
> 
> > I configure NTP once every several years, so I cannot usually
> > remember what's what.
> > 
> > I've got a server that's been running NTP happily for years,
> > seems to stay current, and I'm not going to mess with it.
> > 
> > I've got another machine, glynnis, running RH7.1, and it has the NTP
> > software, but I cannot get it to synchronize with my server.
> > I've looked at my firewall rules, and it seems I have all traffic
> > allowed between these machines, on local-only subnet: 192.168.1.0/24.
> 
> Just in case, port 123 is open for tcp and udp traffic, correct, although
> I note from the docs that it only uses udp.
> > 
> > NTP comes up on glynnis okay, but whenever I run 'ntpq -p' I get
> > this, which tells me btrixie isn't being used, and that the
> > local clock is being taken as the time source:  (btrixie is an
> > entry in my /etc/hosts file, equated to 192.168.1.148)
> > 
> > [root at glynnis init.d]# ntpq -p
> >      remote           refid      st t when poll reach   delay   offset  jitter
> > ==============================================================================
> >  btrixie         0.0.0.0         16 u    -   64    0    0.000    0.000 4000.00
> >  LOCAL(0)        LOCAL(0)        10 u    -   64    0    0.000    0.000 4000.00
> 
> Are you sure that glynnis can reach btrixie?

Absolutely.  On top of the indirect reasons for thinking so, I can see the
traffic in tcpdump(1).

On glynnis, I see:
15:47:25.781322 > bglynnis.ntp > btrixie.ntp: v4 client strat 11 poll 6 prec -17 (DF)

At the same time, on trixie, I see:
16:05:11.283969 fglyn.ntp > ftrix.ntp: v4 client strat 11 poll 6 prec -17 (DF) 

I hadn't noticed before that the /etc/hosts names are not the same on the two
machines, but these are the two in question.  Moreover, the messages are essentially
simultaneous, but the time warp is quite obvious.

At the same time that the above is (not) going on, trixie is doing it's usual
communication with its time sources outside; the difference being that here,
replies are forthcoming:
16:03:32.753185 trixie.kosmanor.com.ntp > clepsydra.dec.com.ntp: v4 client strat 2 poll 10 prec -15
16:03:32.781343 clepsydra.dec.com.ntp > trixie.kosmanor.com.ntp: v4 server strat 1 poll 10 prec -17

> 
> > My configuration file is very simple.
> > 
> > > server 192.168.1.148
> > >  
> > > server  127.127.1.0     # local clock
> > > fudge   127.127.1.0 stratum 10
> > >  
> > > driftfile /etc/ntp/drift
> > > multicastclient                 # listen on default 224.0.1.1
> > > broadcastdelay  0.008
> > >  
> > > authenticate no
> 
> Kurt
> -- 
> Your lucky number has been disconnected.
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-- 
Kevin O'Gorman  (805) 650-6274  mailto:kevin at kosmanor.com
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