Re: [Ntp] Antw: Re: Calls for Adoption -- NTP Extension Field drafts -- Four separate drafts

[Harlan Stenn <[e-mail]>]

On 9/2/2019 3:59 AM, Heiko Gerstung wrote:
> Harlan,
> 
> I am not sure I understand you correctly. My point was that we can change the base format of an NTP packet because we mark it as version=5. If someone sends a request with version=4, he should get a version=4 response with the v4 packet format. If someone sends a version=5 request, they will get a version=5 response with the new packet format, because the v5 request indicated that the client wants and understands a v5 response.
> 
> Maybe we both agree on this one here and just misunderstand each other? ;-)

People are saying that regardless of the version number in the packet,
one should respond with the version the other side offers, with the data
that *we* understand.

How can that possibly work if you want to make a v5 packet that changes
the format and/or content of the base packet?

How can a v4 server that gets a v5 packet possibly respond with correct
v5 data?

> Again, the loop detection algorithm for degree-n-loops would be one benefit from a chain of refids that are passed on from top to down. It would also allow to identify if two or three of my stratum 3 sources get their time from the same stratum 1 source. If we add a flag to the chain that indicates that this InstanceID contributed to the chain using an NTS protected connection, a client could reject any source that is not providing a fully protected chain. Or it prefers a source that can come up with such a chain.

How do you propose getting that refid chain "downstream"?

We've just spent YEARS doing our best to remove meaning from the refid
field to prevent abuse vectors for a single upstream, and now you want a
method to clearly identify a chain of upstreams?

Indeed, for this chain to work one would need to know all the players in
the tree between the top of the heap and the "bottom", as  the loop
detection would need to know the various possible systems in the middle.

When did NTS evolve to provide assertions about the intentions of the
"middle players"?

> Best Regards,
>    Heiko
> 
> 

-- 
Harlan Stenn, Network Time Foundation
http://nwtime.org - be a Member!