Re: Spencer Dawkins' Discuss on draft-ietf-6man-resilient-rs-05: (with DISCUSS and COMMENT)

[Spencer Dawkins at IETF <[e-mail]>]

Hi, Brian,

On Tue, Apr 7, 2015 at 8:30 AM, Brian Haberman <[e-mail]>
wrote:

> Hi all,
>
> On 4/6/15 11:07 PM, Spencer Dawkins wrote:
> > Spencer Dawkins has entered the following ballot position for
> > draft-ietf-6man-resilient-rs-05: Discuss
> >
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> > introductory paragraph, however.)
> >
> >
> > Please refer to http://www.ietf.org/iesg/statement/discuss-criteria.html
> > for more information about IESG DISCUSS and COMMENT positions.
> >
> >
> > The document, along with other ballot positions, can be found here:
> > http://datatracker.ietf.org/doc/draft-ietf-6man-resilient-rs/
> >
> >
> >
> > ----------------------------------------------------------------------
> > DISCUSS:
> > ----------------------------------------------------------------------
> >
> > I'm piling on Barry's Comment as a Discuss, which should be easy to
> > discuss, but ... in this text:
> >
> > 3.  Configuring the use of retransmissions
> >
> >    Implementations of this specification MAY provide a configuration
> >    option to enable or disable the use of such potentially infinite
> >    retransmissions.  If the implementation provides such a configuration
> >    option, it MUST be able to enable/disable retransmissions on a per-
> >    interface basis.
> >
> > You can tell me that it's a LAN, so the transport ADs can go back to
> > sleep, but I was surprised that this configuration option was a MAY.
> >
> > I was also surprised that there was no guidance about the default setting
> > (on or off), but let's start with the MAY.
> >
> > IP does get tunneled to new and exciting places ... and infinite
> > retransmissions are infinite ...
>
> I went back and re-read Barry's Comment and the resulting response and
> felt unsatisfied.
>
> Barry & Spencer, let me know if I am misinterpreting your concerns...
>
> It appears odd to give such concrete guidance as "enable/disable
> retransmissions on a per-interface basis" for a function that is
> completely optional.  After some thought, I am trying to figure out why
> it would be optional since typical NA/NS/RA/RS functionality is
> per-interface anyway.
>
> Given what is being described, I would think we would want to encourage
> implementers to provide a configuration option rather than make it
> optional.  The text could be re-written (without 2119 keywords) as such:
>
> NEW:
> Implementations of this specification are encouraged to provide a
> configuration option to enable or disable potentially infinite RS
> retransmissions. Providing an option to enable/disable retransmissions
> on a per-interface basis allows network operators to configure RS
> behavior most applicable to each connected link.


So, without 2119 keywords, I'd prefer "strongly encouraged", but
"encouraged" is an improvement.

My other point was - if there's a  configuration option for this, I would
prefer that the group make a recommendation about default settings.

I'd prefer "off by default", but could be convinced that "on by default"
has benefits that outweigh the costs.

Without a recommendation, I'm visualizing a network where the option isn't
set, some devices default "on" and others default "off", and hilarity
ensues.

Again, I could be convinced that's not a problem, but wanted to ask.

I'll clear when we figure out what I'm clearing in favor of, but I'll clear
for "encouraged" or anything stronger in the text you proposed.

Thanks!

Spencer