[ntp:questions] Re: Cannot synchronize to server with local clock

Serge Bets serge.bets at NOSPAM.laposte.invalid
Fri Jul 22 11:01:34 UTC 2005


 On Thursday, July 21, 2005 at 7:41:49 AM +0100, David Woolley wrote:

> NTP is not intended to be used with intermittent connectivity.

Yes, it is still weak on dialup. Can be (ab)used though.


> Serge Bets <serge.bets at NOSPAM.laposte.invalid> wrote:
>> a 127.127.1.0 stratum 8 prefer on your server, and another one
>> stratum 14 (but not prefer) on a given client.
> Normal guideline is stratum 10

Wow! :-| Well: So let's say server 10, given client 12.


> I don't believe it should be prefer here.

You are right, thanks: No "prefer" on server in this case! Sorry for the
confusion Tim. I was thinking to another situation where "prefer" helped
avoiding clients division into two subgroups each following own server.


> Local clock on a leaf node is never a good idea

Wait a second: The given client is not a leaf. It is a leaf, most of the
time. But begins serving the whole LAN as soon as (1) Tim is offline and
(2) server is shutdown.


>> only one sync source at a time
> You can, and probably should have, multiple local servers

In isolated or nearly isolated cases, multiple redundant servers peering
at same stratum with each a LOCAL() refclock make not much sense. Much
less sense than if refclocks were something true, GPS, DCF, or such.
Outvoting a falseticker when there is hope of Truth, it's OK. But when
everybody is wandering... In my humble opinion it's calling for
problems, like the sub-island one. For no benefit.

Not exactly. For one benefit: Tolerate shutdown of all but one server.
But this benefit, you also get it with the cascade scheme. And the
cascade scheme has only one sync source at a time, with all clients
hopefully following it. No sub-island risk.

I practice problems will surely happen, especially during transitions.
Tuning needed. Otherwise where would be the fun?


>> Mail-Copies-To: poster
> Please use a valid email address or remove this request from your
> headers. Normal netiquette is not to copy poster.

My reply address is valid and read. I can be followupped, replied, or
both, at will, without any annoying REMOVETHIS bother. My newsserver
sometimes hiccups, so I welcome mail copies. But I don't require it, and
don't want anyone to do extra effort to manually CC me. Hence the
automated only request thru MCT:poster. Compatible newsreaders do send
me a courtesy copy of followups automatically to my Reply-To address,
with perhaps just a confirmation prompt.

There are uncompatible newsreaders not reacting to MCT, or people that
for some reasons don't want to send a CC. That's fine with me.

Normal netiquette is not to copy poster? By default, of course: Dupes
are generally considered harmfull. But if I ask for it? Netiquette was
not against MCT, last time I checked. Some use MCT:nobody to enforce
default no copy. And some use MCT:poster. It's not like if it was the
harsh Followup-To:poster with "Please reply by mail, I don't care
reading your stupid newsgroup." meaning.

I removed MCT for you, but please explain me what is the problem, Dave.


Serge.
-- 
Serge point Bets arobase laposte point net




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