Subject: Re: [RAM] Re: Impending publication: draft-iab-raws-report-01.txt

From: [email-masked] (Noel Chiappa)
Date: Sun, 18 Mar 2007 15:18:12 -0400 (EDT)

> From: Pekka Savola <[email-masked]>

    >>> In a full transition where all sites get a PI prefix, I think that
    >>> the number quoted above is extremely conservative, perhaps
    >>> laughably so.

    >> The document probably ought to say roughly that

Err, my comment was only about the "where all sites get a PI prefix" case,
so I'm not how relevant your comments below are to the point I was
commenting on. Anyway, moving on...

    > what do you (and the draft) mean with 'full IPv6 transition'?
    > ... In any case this probably needs to be clarified.

I agree this could be better defined, since some potential meanings are
almost meaningless - e.g. "every last IPv4-speaking host goes away" won't
happen anytime in our lifetime, probably. So I'd say something like "very
substantial IPv6 transition", and then define it as a percentage of the
size of the IPv4 installed base - not sure what the appropriate %-age
number is.

    > Could someone give some ideas what exactly would contribute the IPv6
    > prefix count? I've trouble figuring how to get to even 100K prefixes

Presumably many (but not all) of the same things that drive fragmentation
in the IPv4 routing tables would drive it in the IPv6 tables too. There's
likely to be less of some (e.g. going back for a second chunk of space
because your initial allocation ran out - although we may still see some of
that) and more of others (e.g. PI-space), and who knows how it will balance
out.

	Noel

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---

From: [email-masked] (Noel Chiappa)
Date: Mon, 19 Mar 2007 09:03:04 -0400 (EDT)

> From: Ross Callon <[email-masked]>

    > ... our understanding of the problem, and of potential solutions,
    > continues to evolve over time ...
    > To what extent is the workshop report supposed to be an accurate
    > description of what went on at the workshop, and to what extent is it
    > supposed to be an accurate description of what we *now* feel is the
    > problem and range of possible solutions? 

Good point. I would say it should be both. IMO it would be misleading to the
general public to publish a document saying "X is possible" when we now know
that X is not possible.

Rather, I think we should both document the meeting, as well as explicitly
point out advances in understanding since then (as much as we know at the time
of publication). To do that, invent some special syntax for labelling such
post-meeting knowledge (and well note it at the start of the document), and
the write things like "The meeting concluded that X is possible. {Note: Since
the meeting, it has been discovered that X is not after all possible, because
of Y.}"

    > I don't think that our understanding of the problem will become
    > static for quite a while ...

Another good point; the document should say this explicitly, again, to warn
people. (There's no point holding the document waiting for out understanding
to stabilize; that's a moving target for a long time to come, is my guess.)

	Noel

---

From: Jessica Yu <[email-masked]>
Date: Tue, 20 Mar 2007 15:47:09 -0700 (PDT)

I think the case John described below do exist. For example, my organization is currently advertising 3 /16's to the global routing table. It is not because of traffic engineering. It's because the prefixes just can not be aggregated due to pre-cidr allocation. In v6 world, one will be advertised.

I do not know how wide spread such situation exist. I would not be surprised that many organizations with pre-cidr address allocation would have the same situation.

cheers!

--Jessica

----- Original Message ----
From: John G. Scudder <[email-masked]>
To: Vince Fuller <[email-masked]>
Cc: [email-masked]; [email-masked]
Sent: Monday, March 19, 2007 12:00:23 PM
Subject: Re: [RAM] Re: Impending publication: draft-iab-raws-report-01.txt

On Mar 18, 2007, at 11:43 PM, Vince Fuller wrote:
> 2) The majority of more-specific prefixes in the global routing  
> system are
>    advertised intentionally for traffic engineering or other  
> purposes. In
>    other words, relatively few more-specifics are configuration  
> errors that
>    would go away if only network operators were better educated.  
> One ipv6
>    prefix would be needed for each of the observed IPv4 more- 
> specifics that
>    are intentionally advertised today. This is 74K prefixes.

Since some of the entities advertising more-specifics have likely  
obtained multiple blocks of address space, from which the more- 
specifics are taken, then it would seem to follow that in the IPv6  
case where we assume that each entity really just needs a single  
address block, they'll advertise fewer more specifics.  That is to  
say, there may be more than one more-specific per site now, because  
of the history of how address blocks were allocated, but in the IPv6  
world one would hope for only a single more-specific per site.

So 74k seems like an overcount, though I imagine not grossly so.   
(I.e., I wouldn't dispute it as a rough estimate, which I guess is  
all it purports to be.)

--John

 
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