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

[Ulrich Windl <[e-mail]>]

>>> Hal Murray <[e-mail]> schrieb am 05.09.2022 um 23:52 in
Nachricht
<[e-mail]>:

> [e-mail] said:
>> SNTP is defined in RFC5905 Section 14. You don't need anything more than
>> that. 
> 
> There is also RFC 4330 and a lot of crappy code out there in firmware that 
> will never get updated.
> 
> RFC 5905 is over 100 pages.  Section 14 is less than a page.  How many of 
> those other pages would somebody have to read and understand in order to 
> implement a SNTP client?
> 
> If you were a junior programmer assigned to implement a SNTP client, would 
> you 
> go throgh RFC 5905 or google around and find some code to copy and ship it 
> when it worked?

Actually I think, the programmer will first write some code, and when that
does not seem to work, he'll add code from elsewhere.

> 
> 
> I think we should have a separate document for SNTP clients.  So far, I 
> haven't convinced (m)any other people.  There are two goals:
> 
> One is to have a clear and simple document so we can point people at it when

> 
> their current code is sending ancient format packets.  Some of those ancient

> 
> packets are not using a format described in any RFC and they worked just 
> because of the undocumented details in the ntpd implementation.
> 
> Another is to make us think and document a packet format that we will 
> support for a long time.

Yes, but a "packet format" does not mean a fixed-length packet IMHO; instead
if should contain a mechanism for a variable number of optional fields that can
have a variable length and should be parseable even if it's only to ignore
them.
I think that is what the e tension fields had in mind, but somewhat
short-sighted.

> 
> We should setup servers that don't support old format packets so SNTP 
> implementors can test their code.

Would it be advantageous if a server can recognize an SNTP request?


Regards,
Ulrich

> 
> 
> 
> ‑‑ 
> These are my opinions.  I hate spam.
> 
> 
> 
> _______________________________________________
> ntp mailing list
> [e-mail] 
> https://www.ietf.org/mailman/listinfo/ntp