Dear colleagues

Version 2 of prop-111: Request-based expansion of IPv6 default
allocation size, did not reach consensus at the APNIC 37 Policy SIG.
Therefore, this proposal is being returned to the author and the Policy
SIG mailing list for further discussion.


Proposal details
----------------

This proposal modifies the eligibility for an organization to receive an
initial IPv6 allocation up to a /29 by request basis.

Proposal details including the full text of the proposal, history, and
links to mailing list discussions are available at:

       http://www.apnic.net/policy/proposals/prop-111

Regards

Andy and Masato



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prop-111-v002 Request-based expansion of IPv6 default allocation size
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Author:       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]. It's better to
   expand this minimum allocation size up to /29 (/32 - /29) since:

   - Before sparse allocation mechanism implemented in late 2006, /29
     was reserved for all /32 allocations by sequential allocation
     method made from those old /23 blocks. These reserved blocks
     might be kept unused in the future.

   - Sparse allocation mechanism was implemented in late 2006 with a
     /12 allocation from the IANA. Under the sparse allocation
     mechanism, there is no reservation size defined, and the space
     between allocations continues to change, depending on the
     remaining free pool available in APNIC.

     However, the "APNIC guidelines for IPv6 allocation and
     assignment requests"[2] stated:

     "In accordance with APNIC's "IPv6 address allocation and
     assignment policy", where possible, subsequent delegations to the
     same resource holder are made from an adjacent address block by
     growing the delegation into the free space remaining, unless
     disaggregated ranges are requested for multiple discrete
     networks."

     So, it is expected that allocation up to /29 is guaranteed for
     consistency with allocations above. Based on the current
     situation, contiguous allocation of /29 can still be accommodated
     even under the sparse allocation mechanism (Current /32
     allocations from the /12 block can grow up to /24 at this stage).

   - For traffic control purpose, some LIRs announce address blocks
     longer than /32 (e.g. /35). However, some ISPs may set filters to
     block address size longer than /32 since some filtering
     guidelines recommend to filter longer prefix than /32([3][4]). If
     LIRs have multiple /32, they can announce these blocks and its
     reachability will be better than longer prefix.

   - If an LIR needs address blocks larger than /32, LIRs may tend to
     announce as a single prefix if a /29 is allocated initially at
     once. i.e., total number of announced prefixes in case 1 may be
     smaller than in case 2.

     case 1:
     The LIR obtains /29 at the beginning of IPv6 network construction.

     case 2:
     The LIR obtains /32, and /31, /30 additionally with the subsequent
     allocation mechanism.

 2. Objective of policy change
-----------------------------
   This proposal modifies the eligibility for an organization to
   receive an initial IPv6 allocation 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
----------------------------

   - Change the text to "5.2.2 Minimum initial allocation size" of
     current policy document as below:

     Organizations that meet the initial allocation criteria are
     eligible to receive an initial allocation of /32. For allocations
     up to /29 no additional documentation is necessary.

   - Add following text in the policy document:

     for Existing IPv6 address space holders

     LIRs that hold one or more IPv6 allocations 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. Explain the advantages of the proposal
-----------------------------------------
   - It is possible to utilize address blocks which is potentially
     unused into the future.
   - It will be possible for LIRs to control traffic easier.
   - Organizations can design their IPv6 networks more flexibly.


6. Explain the disadvantages of the proposal
--------------------------------------------
   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.

7. Impact on resource holders
-----------------------------
   NIRs must implement this policy if it is implemented by APNIC.


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


[2] APNIC guidelines for IPv6 allocation and assignment requests
https://www.apnic.net/publications/media-library/documents/resource-guidelines/ipv6-guidelines

[3] Packet Filter and Route Filter Recommendation for IPv6 at xSP routers
https://www.team-cymru.org/ReadingRoom/Templates/IPv6Routers/xsp-recommendations.html

[4] IPv6 BGP filter recommendations
http://www.space.net/~gert/RIPE/ipv6-filters.html