Dear SIG members
A new version of the proposal "prop-111 Request-based expansion of IPv6default allocation size" has been sent to the Policy SIG for review.
Information about earlier versions is available from:
You are encouraged to express your views on the proposal:
- Do you support or oppose this proposal?- Is there anything in the proposal that is not clear?- What changes could be made to this proposal to make it more effective?
Regards,
Andy and Masato
----------------------------------------------------------------------prop-111-v002 Request-based expansion of IPv6 default allocation size----------------------------------------------------------------------
Author: Tomohiro Fujisaki
1. Problem statement--------------------
IPv6 minimum allocation size to LIRs is defined as /32 in the "IPv6address allocation and assignment policy"[1]. It's better toexpand this minimum allocation size up to /29 (/32 - /29) since:
- Before sparse allocation mechanism implemented in late 2006, /29was reserved for all /32 allocations by sequential allocationmethod made from those old /23 blocks. These reserved blocksmight be kept unused in the future.
- Sparse allocation mechanism was implemented in late 2006 with a/12 allocation from the IANA. Under the sparse allocationmechanism, there is no reservation size defined, and the spacebetween allocations continues to change, depending on theremaining free pool available in APNIC.
However, the "APNIC guidelines for IPv6 allocation andassignment requests"[2] stated:
"In accordance with APNIC's "IPv6 address allocation andassignment policy", where possible, subsequent delegations to thesame resource holder are made from an adjacent address block bygrowing the delegation into the free space remaining, unlessdisaggregated ranges are requested for multiple discretenetworks."
So, it is expected that allocation up to /29 is guaranteed forconsistency with allocations above. Based on the currentsituation, contiguous allocation of /29 can still be accommodatedeven under the sparse allocation mechanism (Current /32allocations from the /12 block can grow up to /24 at this stage).
- For traffic control purpose, some LIRs announce address blockslonger than /32 (e.g. /35). However, some ISPs may set filters toblock address size longer than /32 since some filteringguidelines recommend to filter longer prefix than /32([3][4]). IfLIRs have multiple /32, they can announce these blocks and itsreachability will be better than longer prefix.
- If an LIR needs address blocks larger than /32, LIRs may tend toannounce as a single prefix if a /29 is allocated initially atonce. i.e., total number of announced prefixes in case 1 may besmaller 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 subsequentallocation mechanism.
2. Objective of policy change-----------------------------This proposal modifies the eligibility for an organization toreceive an initial IPv6 allocation up to a /29 (/32 - /29) byrequest basis.
3. Situation in other regions-----------------------------
RIPE-NCC:The policy "Extension of IPv6 /32 to /29 on a per-allocation vsper-LIR basis" is adopted in RIPE-NCC and LIRs in RIPE region can getup to /29 by default.
4. Proposed policy solution----------------------------
- Change the text to "5.2.2 Minimum initial allocation size" ofcurrent policy document as below:
Organizations that meet the initial allocation criteria areeligible to receive an initial allocation of /32. For allocationsup 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 requestextension of each of these allocations up to a /29 without meetingthe utilization rate for subsequent allocation and providingfurther documentation.
5. Explain the advantages of the proposal------------------------------------------ It is possible to utilize address blocks which is potentiallyunused 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 ofIPv6 space since LIRs can obtain huge address size unnecessarily.However, this will not happen because larger address size needshigher 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
[2] APNIC guidelines for IPv6 allocation and assignment requests
[3] Packet Filter and Route Filter Recommendation for IPv6 at xSP routers
[4] IPv6 BGP filter recommendations
* sig-policy: APNIC SIG on resource management policy *
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