:Matthew Dillon wrote:
:> I'm going to do some work on dntpd to try to correct two unrelated
:> issues. First I'll try to have it detect a bad time source when
:> several are available. Second, I'll have it re-run the DNS lookup
:> if a server stops responding and I'll have it detect duplicate IPs.
:
:How about taking the median of offsets to all servers which are considered
"good"? Good would be something like "off less than two times the standard
deviation" or so.
:
:cheers
: simon
I don't think you can quantify the accuracy of a median offset verses
a statistically good offset returned by a single server, so no.
What I did, amoung other things, was add a quorum calculation to the
code. Now it chooses the best server and then requires that a quorum
of servers agree that the offset reported by that server is reasonable.
There might be a way to algorithmically reduce offset errors (due to
packet lag) relative to real time given multiple good sources, but I
haven't researched it.
Another thing we can do is 'lock' to a particular server as long as
its accuracy does not deviate from the current best available by too
much. I have not coded something like that yet.
-Matt
Matthew Dillon
<[EMAIL PROTECTED]>
