[ntp:questions] Re: ntpd, boot time, and hot plugging

Alain alainm at pobox.com
Fri Feb 4 16:47:59 UTC 2005



Brad Knowles escreveu:
>>                                                         Suppose I undock
>>  (taking down eth1) and plug in down the hall with the built-in NIC
>>  (bringing up eth0).
> 
>     You may no longer be anywhere "close" to the upstream time servers 
> you had previously configured, and may have to tear down all your server 
> associations and put up all new ones.
> 
>     Any time you switch interfaces, get a new IP address, or any of the 
> other things that are typical for mobile environments, you're basically 
> looking at a complete stop and restart, if not a complete stop, 
> re-configure (presumably with totally different servers), and re-start.

Woldn normal operation cope with that? If it is a server at all, 
continue with calculated historical drift. If both sets of servers are 
in ntp.conf, after a while it will acquire sync again.

>>                      What must one do to make ntpd tolerant of that?
> 
>     I'm not convinced that is possible.  At least, not in the way you're 
> thinking of.

Maybe just be a bit more tolerant to a situation where all servers 
become unavailable?

And maybe just use longer times to calculate drift if connection times 
are not stable. Just a parameter adjustment maybe?

Alain



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