Re: Gunter Van de Velde's No Objection on draft-ietf-bfd-stability-19: (with COMMENT)

[Jeffrey Haas <[e-mail]>]

Gunter,

A very targeted reply:

On 9/18/25 07:10, Gunter Van de Velde via Datatracker wrote:
> 164        The NULL Authentication Type, defined in this document, can be used
> 165        to provide a meticulously increasing sequence number for stability
> 166        measurement.  It provides none of the protections desired for
> 167        authentication and is used only to provide BFD stability services to
> 168        BFD sessions that otherwise have no authentication in use.
>
> GV> similar as some others i got triggered by the word 'meticulously'.
> Maybe use “strictly increasing” (most operator- and implementer-friendly) or
> “monotonically increasing” (if you want mathematical precision).

Section 6 in secure sequence numbers describes the required property, 
which is not what you've pasted above.  Since we seem to be regularly 
coming back to the fact that RFC 5880 wasn't clear enough we should 
simply draft text covering the property that is acceptable to the IESG 
and paste it into all three documents.

The required property is that when you transmit the next sequence 
number, it is +1 the prior one in a circular numbering space. That's it.

The reason it is "meticulous" is because in RFC 5880, non-meticulous 
modes permitted sequence number re-use as a scaling mechanism.

Strictly and monotonically increasing do not cover the +1 property, only 
that they always go forward.

For the stability draft, the +1 property is required to detect gaps.  
See also discussion about out of order delivery in the draft.

-- Jeff