[routing-wg]On Vince's talk

> Sorry I had to cut the line at the microphone. Hans Peter Holen would  
> you care to send your comment to the list?
> 
> In addition, while watching Vince's presentation, and seeing how the  
> little IPv6 would contribute to the total sum of routes one would be  
> seeing announced to the Internet (internal routes are each ISP's  
> problem in this context, to some extent)

Perhaps I didn't explain clearly enough...

In the analysis given, IPv4 contributes approx 180K globally-visible routes
while ipv6 contributes 82K (21K ASNs plus 61K more-specifics advertised for
TE or other purposes). The remainder of the 350K to 530K routes are customer
and infrastructure internal routes for both IPv4 and ipv6 - it is assumed
that IPv4 and ipv6 contribute an equal number of such routes. Yes, such
internal routes are each ISP's problem but if one believes that large ISPs
will have similar numbers of them, they need to be counted for purposes of
router sizing purposes. It is not clear whether GSE or any other mechanism
for reducing global state would help scale internal state. In any case, even
if we only consider the 180K + 82K = 260K globally-visible routes, an
exponential or quadratic growth trend of in the quantity of that state will
eventually cause a problem. As Geoff so eloquently stated, it isn't the
raw number that is scary, it is the long-term trend. Remember that even an
exponential curve can start off at a very shallow slope... 

> I was wondering what would actually happen towards the time around which
> *new* IPv4 addresses would become scarce and people are forced to change
> the way IPv4 is used (eg, by splitting current allocations and trading
> those smaller chunks).
> 
> Then the question might become, what would the mess look like if  
> there is no IPv6 deployment? and does the picture Vince hinted at  
> become any worse in the absence of IPv6 deployment, even with the  
> less than perfect routing solutions currently available?

These are certainly legitimate questions to ask; the analysis done for this
presentation doesn't really explore them.

One might imagine that a scalable routing and addressing solution for ipv6
(or its successor) might make it more deployable and thus a migration from
IPv4 more attractive.

	--Vince