[ntp:questions] Three NTP servers, one strange IP-address in 'refid'

Brian Utterback brian.utterback at oracle.com
Tue Apr 1 15:39:56 UTC 2014

On 03/31/14 14:44, Sander Smeenk wrote:
> Quoting Rob (nomail at example.com):
>>> | root at dns1:~# ntpq -c lpeers
>>> | ===============================
>>> | *someserver.tld  .PPS.
>>> | +someserver2.tld .GPS.
>>> | -someserver3.tld .PPS.
>>> |  dns2.dns.dmz.bi
>>> |  dns3.dns.dmz.bi
>>> | +someserver4.tld .PPS.
>> So in the above, dns2 and dns3 (two separate servers) both take their
>> time from This is not a server you are talking to, but a
>> server they are talking to.
> Well, yes. You would say that. But dns2 and dns3 *also* sync to
> someserver.tld primarily(*), with two reference/fallback sources(+) and
> one not considered(-). They both show either dns1 and dns2 or dns1 and
> dns3 as syncing to
> I can't find this IP, or any hostname resolving to this IP, in any of my
> configs. So i'm inclined to go with David Woolley's comment: 'refids are
> opaque'. Opaque as that remark may be. ;-))
> -Sndr.

The IP is coming from somewhere. When David said they are opaque he 
means in general. The refid is overloaded and has different 
interpretations under different circumstances and sometimes ntpq can get 
confused about what circumstances are currently in effect. But it seems 
very likely that the IP address is the correct one particularly since 
the first octet matches the first octet of your address space.

It would be helpful if you posted the whole "peers" output, particularly 
for dns2 and dns3.


Always code as if the guy who ends up maintaining your code will be a
violent psychopath who knows where you live. - Martin Golding
Brian Utterback - Solaris RPE, Oracle Corporation.
Ph:603-262-3916, Em:brian.utterback at oracle.com

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