[ntp:questions] NTP client basic

David L. Mills mills at udel.edu
Wed Mar 7 14:51:58 UTC 2007


This is even more bogus. True, current ntpdate does send multiple 
packets, not to different servers, but the same server. The program 
attempts to mitigate the multiple replies in some sense to "improve" the 
accuracy. Presumably, some j-random algorithm is used to do this, but 
not the one used in the specification and reference implementation. I'm 
not going to argue with that other than to point out ntpd operated in 
ntpdate mode already has the crafted algorithms and worthy defenses 
against bogus attacks.


Harlan Stenn wrote:
> Dave,
>>>>In article <esk1um$f7o$1 at scrotar.nss.udel.edu>, mills at udel.edu writes:
> mills> Harlan, SNTP doesn't do anything of the kind. It assumes only a
> mills> single packet exchange resulting in four timestamps to determine the
> mills> time and optional offset and roundtrip delay.
> I was talking about the case where SNTP is contacting several hosts.
> In that case it will send a bunch of packets (one to each host).
> Sorry I wasn't more clear.
> H

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