Re: [Ntp] Antw: draft-ietf-ntp-mode-6-cmds : Issue 1

[Brian Haberman <[e-mail]>]

On 9/19/17 2:52 AM, Ulrich Windl wrote:
>>>> Brian Haberman <[e-mail]> schrieb am 18.09.2017 um 19:10 in
> Nachricht <[e-mail]>:
>> Ulrich noted that this document does not specify a version number for
>> the mode 6 commands. I had suggested specifying it as "version 4 (or
>> earlier)" given that the introduction of mode 6 commands has occurred at
>> various versions of the protocol starting at RFC 1305. Ulrich pointed
>> out that the version number drives the interpretation of the status words.
>>
>> For people who have implemented or use mode 6 commands, what makes sense
>> here? Do we need to specify a version number per mode 6 command?
> 
> Hi!
> 
> I think there are several issues:
> 
> 1) Assuming there are different versions (there are!), how can one find out which version the server implements? See 2)
> 
> 2) if a client requests a version different from the server, what should the server do? The server could respond with a different version number, indicating that it is not willing to respond / privide the information in the format requested. Or the server could respond with a "bad request" status. Finally the server could respond in the format requested... I have slight favor for the first variant unless there is a command to find out what message format versions the server can provide.
> 
> 3) As it seems to be now, the server ignores the version (versions 2, 3, and 4 all seem to work)
> 

The above seems to argue for two things:

1) A preliminary handshake between an NTP server and the mode6-speaking
client to determine what version is in use.

2) A change to the operating basis of the mode 6 commands in that the
above mentioned handshake occurs before actually sending the mode 6 command.

Is that a good representation of what is being asked for?

Brian