Re: UDP/123 policers & status

[Harlan Stenn <stenn () nwtime org>]

I found this as an unsent draft - I hope I didn't send it before.

On 3/30/2020 2:01 AM, Ragnar Sundblad wrote:
> > On 30 Mar 2020, at 08:18, Saku Ytti <saku () ytti fi> wrote:
> >
> > On Mon, 30 Mar 2020 at 01:58, Ragnar Sundblad <ragge () kth se> wrote:
> >
> > > A protocol with varying packet size, as the NTS protected NTP is,
> > > can easily have the bad property of having responses larger than the
> > > requests if not taken care. Don’t you see that?
> >
> > Why? Why not pad requests to guarantee attenuation vector until
> > authenticity of packets can be verified?
>
> Right, and NTS does that.

There is more to NTP than NTS.

Are y'all seriously recommending that NTP always sends a max-sized
packet as a client request so the client/server can send back an
identical response?  That's just wasting huge amounts of bandwidth to
save the possibility of a possibly larger response.

And just becase a responbse may be larger, that doesn't necessarily
translate into an amplification vector.

The alternative seems to be that the client sends a smaller request and
is ready when the response from the server is "Send your request again,
but this time pad it to NNN bytes so I can respond with the same sized
packet"?

> Ragnar

-- 
Harlan Stenn <stenn () nwtime org>
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