Re: [Ntp] Public NTP servers already responds to NTPv5

[Miroslav Lichvar <[e-mail]>]

On Sun, Nov 29, 2020 at 08:43:32PM +0100, Kurt Roeckx wrote:
> On Mon, Nov 30, 2020 at 12:49:09AM +0900, g16 wrote:
> > So I surveyed how the currently public NTP servers respond to NTPv5 packets.
> 
> The draft document probably doesn't make things better. It says to
> just drop the packet in case the version is higher than 5, nor

My intention was to let the future NTPv6 specification describe how
older versions should be handled in the same way this draft allows an
NTPv5 server handle requests with versions 4 and older.

> does it have any text on what a client could do to talk to a
> server that supports older versions.

The client could try NTPv5 and see if it gets a valid response. This
would be similar to the proposed detection of the alternative port.

> So in case a version 6 is ever
> introduced, first the stratum 1 servers have to upgrade, then the
> stratum 2 servers, and so on.

I hope that won't be necessary.

-- 
Miroslav Lichvar