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prop-112-v001: On demand expansion of IPv6 address allocation size in
               legacy IPv6 space
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Proposer:    Tomohiro Fujisaki
             fujisaki@syce.net


1. Problem statement
--------------------

    IPv6 minimum allocation size to LIRs is defined as /32 in the "IPv6
    address allocation and assignment policy"[1].

    In late 2006, sparse address allocation mechanism has implemented
    to manage APNIC IPv6 address pool. The block `2400:0000::/12' has
    managed with this mechanism.

    Before 2006, /29 was reserved for all /32 allocations by sequential
    allocation method made from those old /23 blocks (Legacy IPv6
    block).

    These reserved blocks might be kept unused in the future.


2. Objective of policy change
-----------------------------

    This proposal modifies the eligibility for organizations in the
    legacy IPv6 block to extend their IPv6 address space up to a /29
    (/32 -/29) by request basis.


3. Situation in other regions
-----------------------------

RIPE-NCC:
    The policy "Extension of IPv6 /32 to /29 on a per-allocation vs
    per-LIR basis" is adopted in RIPE-NCC and LIRs in RIPE region can
    get up to /29 by default.


4. Proposed policy solution
---------------------------

    - define 'legacy IPv6 address blocks' 
      2001:0200::/23
      2001:0c00::/23
      2001:0e00::/23
      2001:4400::/23

    - Add following text in the policy document:

      for Existing IPv6 address space holders

      LIRs that hold one or more IPv6 allocations in the legacy IPv6
      address blocks are able to request extension of each of these
      allocations up to a /29 without meeting the utilization rate for
      subsequent allocation and providing further documentation.


5. Advantages / Disadvantages
-----------------------------

Advantages:

      It is possible to utilize address blocks which is potentially
      unused into the future.


Disadvantages:

      Some people may argue this will lead to inefficient utilization of
      IPv6 space since LIRs can obtain huge address size unnecessarily.
      However, this will not happen because larger address size needs
      higher cost to maintain that address block.


6. Impact on resource holders
-----------------------------

      NIRs must implement this policy if it is implemented by APNIC.


7. References
-------------

      [1] IPv6 address allocation and assignment policy
          http://www.apnic.net/policy/ipv6-address-policy