[ntp:questions] NTP Pool Server Costs me $40/mo in Bandwidth--is

Jason Rabel jason at extremeoverclocking.com
Sun Jun 15 01:02:09 UTC 2014


Brian,

A few things you did not mention in your post or your article...

What bandwidth setting (Net Speed) did you specify on the NTP Pool website for your server? What Zone(s) is it listed in?


Also, can you provide a link to your NTP Pool server's page? The URL would look something as follows (this is my server):

http://www.pool.ntp.org/scores/216.230.228.242


I have my net speed set to 10Mbit and my server averages about 20 NTP packets per second and can peak up to 70/sec under normal
traffic. I could bump it higher, my colo'ed server includes 10TB of bandwidth a month (and I'm nowhere near that), but I prefer to
incrementally bump it up and see how traffic is affected.

What does your NTP configuration look like? Specifically any 'restrict' and 'discard' lines would be most helpful.

As someone else already posted, you should have some minimal settings configured to prevent someone 'pounding' your server, please
check the following page:

http://www.eecis.udel.edu/~mills/ntp/html/accopt.html


There seems to be a lot of discussion about whether to use the KoD setting or not (for various reasons). I personally fall into the
group that prefers / recommends NOT to use that variable and instead use various rate limiting methods to prevent abuse (whether
intentional or accidental).


If you are running Linux you can do rate limiting with iptables rather easy too.

No client should be querying more than once every second (or maybe it's every 2 seconds), that is the speed iburst does. Regular
query intervals would be much longer.



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