[ntp:questions] NTPD concurrent clients limit

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Wed Aug 13 22:47:01 UTC 2008

>His question can be rephrased, what does ntpd do after it has sent the Kiss of Death?
>does it drop all subsequent packets? -- That sounds like a huge cost on the
>ntp server-- ie imagine a popular server with 10,000 machines it has sent
>the KoD to. It then has to scan that whole list for each packet to see if
>it is in there-- something which takes time and destroys the ability of ntp
>to deliver its time base rapidly.

A hash table would solve that problem.  (assuming you wanted to
keep track of many many clients)

Note also that scanning a long list won't destroy the accuracy.
NTP uses 2 time stamps, one when the packet arrives and one
when the packet exits.  In between you can do all sorts of things,
for example crunch away for a while doing crypto stuff.

These are my opinions, not necessarily my employer's.  I hate spam.

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