On Jan 27, 2014, at 9:20 PM, Guangliang Pan <gpan at apnic dot net> wrote: > I think that statement refers to early IPv6 allocations from the old /23 blocks. Before APNIC received the /12 allocation from IANA, we use sequence allocation method to make /32 allocations and reserved up to /29 for every allocation. That was the practice for all RIRs in the early stage. I believe this policy proposal is trying to address those reserved space. That wasn't clear from my reading of the proposal, e.g., the first sentence of the problem statement says: "... while APNIC currently reserves up to /29 for each /32 allocation." > APNIC has been using spare allocation method to make IPv6 allocations from the /12 block since we received it from IANA. We don’t do reservation in sparse allocation, but in fact every allocation has a room to grow. Thanks for confirming. > Current /32 allocations from the /12 block can grow up to /24 at this stage. Err. That suggests APNIC is not using sparse (aka bisection) allocation, rather APNIC now just reserves the the /24 instead of the /29...? In any event, looking at the proposal, I gather there are 3 justifications are provided for a default /29: 1) traffic engineering, since some folks out there filter on /32 boundaries; 2) potentially fewer prefixes if the ISP needs to expand 3) efficiency Going in reverse order: I don't understand #3. In this context, is the "efficiency" mentioned related to ease of network design? WRT #2, if I understand correctly, all APNIC allocations for ISPs have sufficient space for that allocation to grow to (at least) a /29 within a single prefix. I don't think APNIC staff would be so silly as to allocate from the reserved/extension space non-contiguously. That leaves #1 which appears to assume the same folks who are currently filtering on longer than /32 won't decide to start filtering on longer than /29. After all, I can easily see the whole point of filtering on /32 by (arguably) overly pedantic network operators as trying to discourage folks from shattering their allocations for traffic engineering purposes to try to limit routing table growth. Once APNIC makes /29 the default allocation size, they could just as easily shorten their prefix filters. Then what, make the default a /24? Are there any data on how many ISPs are filtering at /32? Regards, -drc
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