Re: IP4 Space

[Owen DeLong <owen () delong com>]

On Mar 23, 2010, at 5:17 AM, William Herrin wrote:

> On Tue, Mar 23, 2010 at 3:40 AM, Owen DeLong <owen () delong com> wrote:
> > On Mar 22, 2010, at 10:27 PM, Mark Newton wrote:
> > > On 23/03/2010, at 3:43 PM, Owen DeLong wrote:
> > > > With the smaller routing table afforded by IPv6, this will be less expensive. As a result, I suspect there will be 
> > > > more IPv6 small multihomers.
> > > > That's generally a good thing.
> > >
> > > Puzzled:  How does the IPv6 routing table get smaller?
> > Compared to IPv4?  Because we don't do slow start, so, major providers won't be
> > advertising 50-5,000 prefixes for a single autonomous system.
>
> On the other hand, smaller ASes still announce the same number, the
> hardware resource consumption for an IPv6 route is at least double
> that of an IPv4 entry, RIR policy implies more bits for TE
> disaggregation than is often possible in IPv4 and dual-stack means
> that the IPv6 routing table is strictly additive to the IPv4 routing
> table for the foreseeable future. Your thesis has some weaknesses.
With 30,000 active AS right now, assuming an average of 2 instead of 9.5,
even if we double the number of active AS every 5 years, we're still looking
at 10 years for the IPv6 routing table to catch up.

30,000 * 2 = 60,000 prefixes today
120,000 prefixes in 5 years (60,000 active AS)
240,000 prefixes in 10 years (120,000 active AS)

I think that the additive nature of the IPv6/IPv4 routing tables  will be the
driving factor for deprecation of IPv4 pretty quickly once IPv6 starts to
reach critical mass.  The problem is that we are so early on the IPv6
adoption curve right now that nobody believes IPv6 will become
ubiquitous fast enough to be relevant.

I think that IPv6 deployment is already showing signs of acceleration.
I think that it will lurch forward suddenly shortly after (~6-12 months)
IPv4 finally hits the runout wall in a couple of years.

Owen