[ipv6-wg] 96 more bits... time for some magic after all?

Hi Shane and list,

Shane Kerr <shane at time-travellers.org> writes:

> All,
>
> [ gah... hit the wrong key and sent this unfinished ]
>
> We saw two presentations by network architects at the RIPE meeting that
> used bits in their IPv6 addressing plan to carry meaning beyond simple
> network topology and packet routing.
> [...]
> This includes the long-standing historical goals of conservation,
> aggregation, and accuracy.
>
> Using bits in IPv6 networks for other purposes is orthogonal to those
> goals. 
>
> What should we do about it?

as long as they don't need more than "their share" of the address space
as defined by the policy applied to everyone: Nothing.

More important however is the question how to deal with them if /when
they show up because they have unnecessarily "depleted" their address
assignment thanks to encoding stuff in it.  I strongly suggest to send
them home to renumber their network (and hope it hurts enough to teach
them and everyone watching a lesson).

It's not much different than with IPv4.


Beyond that, there are some more aspects to consider:

- Work the numbers.  With IPv4 addresses and 32 bits we have kind of
  managed to come to grips at an intuitive level.  With IPv6, this
  simply doesn't work anymore; a /29 for Deutsche Telekom is
  ok. However, if they start to code more stuff into the addresses, this
  will quickly break down.  In other words: No matter what, 128 bits are
  still just 16 bytes.  If other people follow suit and start to encode
  things in their addresses, we may run out of space *very* quickly.

- Remember that they effectively nicked the extra five(?) bits from the
  subnet ID, by handing out /56s instead of /48s as originally
  intended.  They can only do that so often.

- I assume you all know about the black/grey market for IPv4 by now.
  This isn't a technical thing, but a "business model".  People will
  again receive allocations they don't need, and we will see some sort
  of artificial, money-driven depletion of the IPv6 address space as
  well.  If this gets "successful" before we have to move on from IPv6
  for unrelated reasons, or if this will again cause us to run out of
  addresses before anything else becomes a critical issue, is open for
  speculation.  The only solution to that would have been variable
  length addresses, and they bring another bunch of problems of their
  own.


Cheers,

    Benedikt

-- 
			 Business Grade IPv6
		    Consulting, Training, Projects

Benedikt Stockebrand, Dipl.-Inform.        http://www.stepladder-it.com/