[time-nuts] can of worms: time-of-day in a community radio station

[Hal Murray]

attila at kinali.ch said:
> This is a pretty baseless fear. The servers in the ntp pool are constantly
> monitored and those that are off by more than 100ms are quickly removed
> (within 2-3 hours, IIRC). Of course, if you are already using one of those,
> then the removal will not help you. But you are most likely using 3-5 servers
> anyways, which means ntp will remove the "rouge" server on its own. 

It's more complicated than that.

It depends on what code you are using and how you configured things.

If you are using  ntpd and you said in your ntp.conf
  server <pool>
Then it grabs one and sticks with it until you restart ntpd.

In the old days, it was common to use
  server 0.pool
  server 1.pool
  server 2.pool
  server 3.pool
That used the pool before the pool code in ntpd was working.  I'm pretty sure 
some distros set things up that way and some systems are probably still using 
an old config file.

The pool code is supposed to drop bad servers and get replacements.  I'm not 
sure of the details on what "bad" covers.  It could be not responding at all 
or it could be time not good-enough.  I'll dig into the code if it matters.


If you aren't running ntpd (classic or ntpsec) then I don't know what happens.


-- 
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