[ntp:questions] NTP behaviour when server is not synchronized
geir.guldstein at start.no
Fri Jun 29 18:28:27 UTC 2007
On 29 Jun, 20:07, Harlan Stenn <s... at ntp.isc.org> wrote:
> >>> In article <1183138077.657644.124... at n2g2000hse.googlegroups.com>, Geir G <geir.guldst... at start.no> writes:
> Geir> Hello, NTP configuration:
> Geir> Client: ntpd version 4... at 1.1532 running on Windows XP Servers: 2
> Geir> identical stratum 1 servers with GPS antennas directly connected
> Are these 2 servers peering with each other? They should be.
Please note that the servers are embedded devices and (at least to my
knowledge) don't run the NTP reference implementation. I don't think
they support peering.
> Geir> I want comments on the following observations. Unfortunately, the
> Geir> system is currently not available, hence I cannot supply ntpq
> Geir> diagnostics. I know that 2 servers is the worst possible
> Geir> configuration, it is not necessary to comment that.
> Geir> For some reason one NTP server lost its GPS synch. It switched to
> Geir> internal clock started reporting stratum 12 when this happened. The
> Geir> other server was perfectly synchronized and reported stratum 1.
> Geir> Problem: ntpd rejects both servers and considers itself not
> Geir> synchronized.
> This tells me it was not peering with the other S1 server. If it was, it
> would report S2 and follow the time of the other S1 server.
OK, you are correct.
> Geir> Questions:
> Geir> 1. Does the NTP server behave correctly when changing its stratum to
> Geir> 12? Should it perform different/other actions when it considers itself
> Geir> not synchronized?
> If it is reporting S12 then you must have it configured to use its local
> clock as a refclock. ntpd is correctly reporting that it is sync'd to its
> local refclock.
> ntpd is behaving as designed. It may be that your configuration is
No specific configuration was done to the server to make it use its
local clock. It seems this is the the default behavior for the device.
> Geir> 2. Does ntpd behave correctly? Is a server's stratum used in any way
> Geir> in ntpd's clock selection process?
Is that 'Yes' to both questions?
> Have you visitedhttp://support.ntp.org/Support/ConfiguringNTP?
Yes, I have. But sometimes it is more convenient to ask the experts
directly. Thank you for your answers Harlan.
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