[ntp:questions] Best practices for leaf nodes
Richard B. Gilbert
rgilbert88 at comcast.net
Wed Nov 28 17:08:48 UTC 2007
Dag-Erling Smørgrav wrote:
> Can anyone point me to a document that describes best practices for a
> leaf node using SNTP to synchronize its local clock? I am particularly
> interested in recommendations regarding how often to poll the server and
> how to behave if no answer is received.
Do NOT poll the server more often than once in 64 seconds! If you get no
reply from a server, double the interval after each failure until you
get to 1024 seconds. If you get no reply after twenty-four hours, quit
wasting your time and network bandwidth and try a different server.
This is documented in the RFCs for NTP and SNTP (RFC-1305 and RFC-4330.
I think you'll find RFC-1305 nearby but I'm too lazy to look it up for you.
Given the limitations of SNTP it is probably sufficient to poll two or
three times a day.
Thank you for inquiring. Several people have created mini-disasters by
getting this wrong. See; e.g.
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