Re: IPv4 address length technical design

[Owen DeLong <owen () delong com>]

On Oct 3, 2012, at 3:49 PM, Jimmy Hess <mysidia () gmail com> wrote:

> On 10/3/12, Jay Ashworth <jra () baylink com> wrote:
> > So the address space for IPv8 will be...
> > </troll>
>
> In 100 years, when we start to run out of IPv6 addresses,  possibly we
> will have learned our lesson and done  two things:
>
>  (1)   Stopped  mixing the Host identification and the Network
> identification into the same bit field;   instead  every packet gets a
> source network address,  destination network address, AND  an
> additional  tuple of       Source host address,   destination host
> address;  residing in completely separate address spaces,  with  no
> "Netmasks",  "Prefix lengths", or other comingling of  network
> addresses and host address spaces.

Agreed, mostly.

Prefix lengths can still be useful for route summarization and it would
be useful to have separate segments of the network address, such as
Autonomous System Number, Intra-AS Organizational Identifier, and
Intra-Organizational Network, for example. It might be useful to use
prefix lengths in those cases to allow for variability in the boundary
between these identifiers.

> And
>  (2)  The new protocol will use  variable-length address for the Host
> portion, such as  used in the addresses of CLNP,  with a convention of
> a specified length,  instead of a hardwired specific limit  that comes
> from using a permanently  fixed-width field.

On this, I disagree… Once host identifiers are no longer dependent on or
related to topology, there's no reason a reasonable fixed-length cannot
suffice.

> Need more bits?   No protocol definition change required.

Nope, just new ASICS everywhere and no clear way to identify where they
are or are not deployed and…

Owen