Number of configured servers

so, I have 6 good stratum1 timeservers where connected with delay 3-15 ms. Can I add prefer to one server or I no need do this? What does mean “prefer”?

grep server /etc/ntp.conf | grep -v ‘#’
server -4 ntp3.*** iburst
server -4 ntp2.*** iburst

Should I add prefer for server “national time standart” or I no need this? Like this
server -4 ntp3.*** iburst prefer
server -4 ntp2.*** iburst

?

It can be add more clock offset stability?

Hi, personally I’d leave ntpd to make it’s own mind up, because you can guarantee once you set one as prefered it, or the link to it, will go down! :wink:

“prefer”: http://doc.ntp.org/4.2.6/prefer.html#prefer

The latency of the internet is always going to be the biggest factor. Depending which flavour of daemon you’re running it may be worth looking at things like temperature compensation in chrony, …or investing in a local GPS receiver.

You really shouldn’t use the ‘prefer’ keyword on a production machine. I’ve only used it for testing to help force a local time source faster. You really should just let the ntp selection algorithm do its thing.