[ntp:questions] NTPD concurrent clients limit

Danny Mayer mayer at ntp.isc.org
Sun Aug 17 01:15:26 UTC 2008


As you and I discussed at the time this is not true of any client 
ignoring the indication of a KOD packet. They will in fact drift further 
and further way from the correct time each time it receives a KOD 
packet. Note that KOD packets are not problem for clients following the 
normal rules of engagement and not bombarding the server.


David L. Mills wrote:
> Phil,
> You refer to the U Wisconsin incient, but there have been several 
> others, including those at NIST and USNO reported in the PTTI paper in 
> my list of publications. The rate controls can be used to selectively 
> drop abuse packets or to return a KoD in the hope that abusers will 
> listen and reduce the rate. Frankly, in the culture of modern times I 
> doubt very much the abuser will listen. After some discussion with my 
> friends here, a further defense was implemented with result the KoD time 
> returned reveals no influence of the server. It's not wrong, it just 
> doesn't result in a time adjustment.
> Dave

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