[ntp:questions] poll interval - Clarification! - RFCcompliancequestion

Anton Persson A anton.a.persson at ericsson.com
Thu Jun 19 07:41:03 UTC 2008


Hi,

(Steve Kosteckes reply follows further down)

I am not expecting anything, I first asked if an explicit requirement
found in RFC 4330 (SNTPv4) is also, implicitly, valid for the RFC
defining
the NTPv3 standard (RFC 1305). The requirement in RFC 4330 is as
follows:

A client SHOULD increase the poll interval using exponential
       backoff as performance permits and especially if the server does
       not respond within a reasonable time.

As you should understand, this is not an explicit requirement found in
RFC 1305,
but I would like to know if it is an implicit requirement, or if it is
implemented
anyway in ntp v4.2.4 (as distributed in Red Hat Enterprise Linux). I.e.
should
I expect ntp v4.2.4, as distributed in RHEL, to use this exponential
backoff
when I forcefully configure it to use NTPv3 and the connection to the
NTP server
is lost? And, if it does indeed implement this even when using V3, how
long should
it take for NTP to increase the poll interval from 64 to 128 seconds?

Some people are asking me why we are forcing it to use NTP v3, the
reasons for
this is that our test-environment is also using ntp v4.2.4 from SUSE,
but the
target environment is using a NTPv3 implementation (I am not aware of
exactly
which implementation this is, but it is not important for a test where
the
server has stopped responding). We don't have access to the target
environment
in such a way that we can always run tests against it, so therefore we
force
ntp 4.2.4 to use v3 explicitly.

   Best regards, Anton Persson

-----Original Message-----
From: questions-bounces+anton.a.persson=ericsson.com at lists.ntp.org
[mailto:questions-bounces+anton.a.persson=ericsson.com at lists.ntp.org] On
Behalf Of Steve Kostecke
Sent: den 18 juni 2008 18:03
To: questions at lists.ntp.org
Subject: Re: [ntp:questions] poll interval - Clarification! -
RFCcompliancequestion

On 2008-06-17, Anton Persson A <anton.a.persson at ericsson.com> wrote:

> The poll interval is 64 to 1024, seconds. ntpd starts up, locks on 
> target, stays synchronized for a while, then we pull the plug.

What are you trying to prove by "pulling the plug"?

> The poll interval is at this time still 64 seconds, how long should it

> take to step up the interval to 128 seconds for a completely failed 
> link?

Why would you expect the poll interval to change if ntpd is not
receiving replies to polls?

--
Steve Kostecke <kostecke at ntp.org>
NTP Public Services Project - http://support.ntp.org/

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