[ppml] Solicing comments: IPv4 to IPv6 Migration IncentiveAddress Space

[Howard, W. Lee]

> -----Original Message-----
> From: wherrin at gmail.com [mailto:wherrin at gmail.com] On Behalf 
> Of William Herrin
> Sent: Wednesday, June 27, 2007 10:55 AM
> To: Howard, W. Lee
> Cc: Scott Leibrand; ppml at arin.net
> Subject: Re: [ppml] Solicing comments: IPv4 to IPv6 Migration 
> IncentiveAddress Space
> 
> On 6/27/07, Howard, W. Lee <Lee.Howard at stanleyassociates.com> wrote:
> > >  Since IPv6
> > > addresses are 4 times the size of IPv4 addresses, that would 
> > > increase the memory demand on routers by a factor of 4. A 
> factor of 
> > > 5 if you consider that they also have to maintain the IPv4 table.
> >
> > "2 to the 64th power" is significantly more than
> > "4 times (2 to the 32nd power)."
> > There are roughly 4 billion addresses in IPv4.
> > There are roughly 18 quintillion subnets in IPv6.
> >
> > 18,000,000,000,000,000,000 > 4*4,000,000,000
> 
> The question was: how would this proposal impact the routing 
> table. In the worst case scenario, this proposal would place 
> the same number of routes in the IPv6 table that are 
> presently in the IPv4 table: roughly 220,000.

Only if:
- everyone who will be connected is already connected, 
- everyone who will have a prefix already has a prefix,
- every prefix that has been assigned or allocated is announced.

These may be true enough that debating them doesn't matter, but
your math wasn't clear to me.

Also, I note Jeroen's correction: with 32-bit ASNs, there are 
a possible 4 billion multihomed sites, each typically 
announcing at least one prefix on two paths.


Lee