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Re: [ppml] Policy Proposal: IPv6 Assignment Size Reduction
Thus spake "David Conrad" <firstname.lastname@example.org>
On 10/30/07 2:53 PM, "Brian Dickson" <email@example.com> wrote:
I have, however, argued that ISPs returning to RIRs for PA blocks, is
bad for the Internet.
Only if those new PA blocks can't be aggregated.
... and only if there's a non-trivial number of them.
Realistically, if LIRs are handing out /48s (or /56s, grr) to every
customer, there's only a handful in each region that would run out of space
in a /32 and would need to come back for more -- which was the point, IIRC.
Plus, those are the exact same folks that are asking for (and getting) more
than a /32 to start with.
Avoiding repeat PA assignments to ISPs, is the *primary*
motivation for the proposals, both at the IETF (6man) and ARIN
The simplest way to do reduce the impact of multiple PA assignments
would be for the RIRs to assign address space in a sparse fashion
such that additional allocations could be done by simply subtracting
a bit from the allocated prefix length. In fact, the RIRs promised to
do this when the /12s were allocated by IANA (last I checked,
however, only APNIC was doing it).
Yes, allocating via bisection would help with that quite a bit. Currently,
it appears ARIN is allocating /32s out of a reserved /29 for each LIR, which
allows 3 bits of growth for each before a second prefix hits the DFZ. That
doesn't seem to be enough at first glance.
However, the few mega-ISPs out there are asking for blocks larger than a /32
(e.g. /27 and /29), and those larger blocks appear to be coming out of
reserved /21s (in ARIN's region). That's a lot of bits for growth for the
folks that indicate they don't expect a /32 to be sufficient in the long
run. If that still turns out to be insufficient, I'm not so worried about
AT&T, VZB, et al announcing two or three aggregates as I am them announcing
hundreds to thousands of intentional (e.g. TE) deaggregates.
Are we trying to solve the right problem here?
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking