[ntp:questions] Broadcast mode

Martin Townsend mtownsend1973 at gmail.com
Mon Sep 12 10:57:20 UTC 2016


Hi,

Currently the network is completely isolated but I did hear rumours
that the master device may in future have a dedicated link to a server
that could potentially be running an NTP Server.  Not sure if this
will ever happen but I will use stratum 5 just in case.  You say this
is default so if I use "server 127.127.1.0" there is no need to have
the fudge statement?

Cheers,
Martin.

On Mon, Sep 12, 2016 at 11:47 AM, Martin Burnicki
<martin.burnicki at burnicki.net> wrote:
> Harlan Stenn wrote:
>> Martin Burnicki writes:
>>> on the server:
>>>
>>> server 127.127.1.0
>>> fudge 127.127.1.0 stratum 0
>>
>> Martin, why do you recommend stratum 0 instead of leaving the default,
>> stratum 5?
>
> Because it basically doesn't matter in an isolated network where a
> free-running clock is used as the main time source if you set the local
> clock stratum to 0, 1, or 5, except that some non-ntpd clients may look
> at the stratum and may not accept the server if the stratum is too high.
>
> *If* there is a different time source available to the server then I
> agree stratum 5 would be a better choice for the local clock.
>
> [...]
>>> This is not accepted by some NTP implementations, and I'm not sure if
>>> ntpd as client would even accept a stratum 5 server, broadcast or not.
>>
>> The default stratum for a local refclock should be just fine.
>
> Oops, In the above paragraph I meant a stratum 15 server, if the local
> clock stratum was fudged to 14, as suggested by the OP.
>
> Martin
>


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