[ppml] IPv6, Vista, and the Popular Press [more]

[Mark Smith]

On Mon, 11 Jun 2007 05:32:57 -0400
John Curran <jcurran at istaff.org> wrote:

> At 5:16 AM -0400 6/11/07, John Curran wrote:
> >At 4:58 PM -0600 6/8/07, Sean Reifschneider wrote:
> >>I have heard that a large part of the reason IPv6 is 128 bits of address
> >>space instead of 64 is that a significant number of people on the committee
> >>didn't fully understand that 64 bits is way way more than twice the number
> >>of addresses we have with IPv4.
> >
> >The folks on the IPNG Directorate may have disagreed quite
> >a bit over various requirements for IPng, but it was not from
> >being unable to comprehend the size of the address space.
> 
> For clarity:  IPv6 address length was set by the IPng Directorate prior
> to the IPv6 working group coming into existence (i.e. in the 1993 to
> mid-1994 timeframe).  I was a member of this Directorate.
> 

By the sounds of it John can probably provide a lot of first hand
detail, however, in addition to that, Christian Huitema's book, "IPv6 :
The New Internet Protocol", 2nd Edition, provides a lot of explanation
of the rational behind a lot of the decisions.

>From what I understand from that book, the original IPv6 addressing was
64 bits in size. However, to allow for deriving node addresses from
IEEE MAC addresses, and allowing for those to be increased from 48 to
64 bits, the decision was made to make the node address portion of the
address 64 bites, and then to make the network portion also 64 bits.

Regards,
Mark.