[ntp:questions] Re: To many servers
Richard B. Gilbert
rgilbert88 at comcast.net
Fri Apr 1 19:03:53 UTC 2005
Joshua Coombs wrote:
>Is there such a thing as configuring too many servers, or is the general
>theory the more the merrier?
>
>Joshua Coombs
>
>
>
>
I believe that there is a limit of ten. Four is the minimum to protect
you against one falseticker. Five protects you against two falsetickers
and seven protects against three falsetickers. Two servers is the worst
possible configuration, for it is written that "A men with two clocks
can never be certain what time it is!"
Careful selection rather than quantity is the key to success. The
maximum error in transmitting time from a server to a client is one half
the round trip delay so you want low numbers for delay. Some network
servers seem to be rock solid; i.e. they have a consistent notion of
what time it is. Other servers seem to wander +/ 25 to 30 milliseconds
around the correct time. Keep an eye on the servers you are using and
see how they compare with each other, then replace the worst one if you
can find a better one.
Configure four or five of the best you can find.
More information about the questions
mailing list