[Ntp] Antw: Re: Antw: [EXT] NTPv5 Loop Detection without Stratum

[Ulrich Windl <[e-mail]>]

>>> Danny Mayer <[e-mail]> schrieb am 30.08.2022 um 00:37 in
Nachricht <[e-mail]>:

> On 8/24/22 1:54 AM, Ulrich Windl wrote:
>>>>> Heiko Gerstung <[e-mail]> schrieb am 23.08.2022 um 12:21
>> in
>> Nachricht <[e-mail]>:
>>> One way of avoiding/detecting loops:
>>> - upon startup, an NTPv5 instance creates a random 64bit ID
>>> - we add a loop detection EF that can include n IDs (or we use n EFs)
>>> - a stratum one server, when ask for his "sync trace", responds with only
>>> his ID
>> Considering that a stratum-1 server may have more than one reference clock
>> (say m) to pick, I think a stratum-1 server should actually prepare one ID 
> per
>> reference clock. It's a design issue whether to return one ID that is 
> different
>> for each clock (see below), or two IDs (server's + clock's).
> 
> No need. When it's a stratum-1 server the referenceID in the packet 
> indicates the clock being used. See RFC5905 Figure 12.

But if the Reference ID for all GPS clocks would be "GPS ", wouldn't he new "loop avoidance" algorithm consider all those to be the same source, thus a loop? So we could not have redundant GPS sources any more???

Regards,
Ulrich
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