[ntp:questions] Re: What's different about these (S)NTP servers?

gabriel rosenkoetter grosen at cc3.com
Thu Oct 30 00:20:38 UTC 2003

On Wed, Oct 29, 2003 at 02:50:53PM -0800, Danny Mayer wrote:
> I don't know what this A.B.C.160 stuff is.

It's a rather common way of hiding my globally-addressable IP
address space from a public mailing list (one gatewayed to a Usenet
newsgroup, no less, and so archived in a variety of places on the
world-wide web) so as to avoid unwanted visitors. I find it hard
to believe you've never seen its use before.

> It has no meaning.

Sure it does. A, B, and C are variables for the same numbers each
time. The real numbers are irrelevant, and expose my internal
networking in a way that I view to be a security threat.

> You should A) upgrade to 4.2.0 and try again

This is a corporate environment, I (or, more importantly, my
management) would rather not use non-vendor-supplied software
packages if it's at all avoidable. I'm sure you must have
encountered this attitude before; it stems from vendors pointing
fingers first at the usage of software other than what they provided
(or stated support with; think Oracle) if a problem is ever brought
to them.

> B) don't use w32time on a PC since you can't guarantee what to
> do. Install ntp 4.2.0 on the W2K machines and turn off the w32time
> service. Things should work between like applications. I don't know
> what kinds of protocols that w32time supports.

w32time is well-documented to support a subset of NTP, called SNTP
(S for simple), which Microsoft "embraced and extended".

My problem is not that the NTP versions I'm using don't work with
w32time servers, but that they don't work with w32time on one
specific server, while they do on others, and give me no indication
for the reason that they don't work. This inconsistent behavior,
across a wide number of NTP versions, leads me to ask here what my
steps for diagnosis should be.

Your preference against Microsoft software is understood, and I
share it, but it's bigotry to suggest that NTP, ostensibly an
implementation of an open standard, must be used everywhere to use
that open standard. That's very poor open source advocacy, and it's
exactly ignoring the questions I asked. Please, if you can't respond
helpfully, don't; you're just wasting everyone's bandwidth.

So, what would lead ntpdate to communicate with two (SNTP) servers,
get seemingly functional results out of both, but refuse the data
received from one and accept the data received from another?

Or, if that's too vague a question, what can I do to get further
information out of ntpdate? (ntpq, unfortunately, won't work with
these servers, as the control channel is one of the pieces of the
implementation missing in SNTP.)

I'm glad to build and entry a newer or modified version of NTP in
the interest of diagnosis, of course. I'll go see what ntpdate
4.2.0 has to say about these two servers.

gabriel rosenkoetter / grosen at cc3.com / CC3 Unix & Linux sysadmin

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