[ntp:questions] What exactly does "Maximum Distance Exceded" mean?
joegwinn at comcast.net
Fri Mar 27 22:21:41 UTC 2009
In article <ywn94oxs3u9t.fsf at ntp1.isc.org>,
Harlan Stenn <stenn at ntp.org> wrote:
> >>> In article <joegwinn-9C92E9.21153416032009 at news.giganews.com>, Joseph
> >>> Gwinn <joegwinn at comcast.net> writes:
> Joseph> In article <ywn9tz5tflz6.fsf at ntp1.isc.org>,
> Joseph> Harlan Stenn <stenn at ntp.org> wrote:
> >> >>> In article <joegwinn-6FD03A.17481615032009 at news.giganews.com>, Joseph
> >> >>> Gwinn <joegwinn at comcast.net> writes:
> >> >> I think you are talking about one of my pet peeves:
> >> >>
> >> >> http://support.ntp.org/bin/view/Dev/NtpVariablesAndNtpq
> Joseph> I don't think that I have inconsistent versions of ntpd and ntpq,
> Joseph> because both came off the same CD from Sun Microsystems.
> >> It's still the same beast. The bottom line is we currently have opaque
> >> data being presented to the user, and that is either being offered
> >> directly to the user (in your case) or is being potentially mis-converted
> >> by ntpq.
> Joseph> I have a lot of trouble believing that Sun put inconsistent versions
> Joseph> on their Solaris install CDs.
> I was not talking about the inconsistent version problem. I'm talking about
> opaque data.
> Joseph> Nor am I using NTPQ for decoding. I decode these codes myself,
> Joseph> following Appendix B of RFC-1305. It turns out that NTPv4 uses the
> Joseph> same definitions. See
> Joseph> <http://www.eecis.udel.edu/~mills/ntp/html/monopt.html>.
> Then I may have misunderstood.
> My point is that while it's fine for ntpd to send "encoded data", I think we
> need to have a way for that data to *also* be sent decoded, or provide
> enough information so programs like ntpq can decode the result, regardless
> of which version of ntpd they are talking to.
It isn't quite bulletproof, but my decoder code also tells NTPv3 and
NTPv4 loopstats and peerstats records apart, keyed on (loopstats?)
One can only hope that NTPv5 et seq will ensure that that an
unsupervised and simple decoder program is able to tell record formats
from various NTP versions apart.
As for a decoded format, that is pure ascii, that would certainly be the
unix way, and would impose negligible load on all but the most skeletal
of embedded systems.
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