nanog mailing list archives

Re: Using IPv6 with prefixes shorter than a /64 on a LAN


From: Mark Andrews <marka () isc org>
Date: Mon, 07 Feb 2011 08:57:14 +1100


In message <4D4EB93E.6000409 () brightok net>, Jack Bates writes:
On 2/5/2011 11:57 PM, Mark Andrews wrote:

Rationalising to power of 2 allocations shouldn't result in requiring
256 times the space you were claiming with the 8 bits of shift on
average.  A couple of bits will allow that.

I didn't claim 8 bit average (if I accidentally did, my apologies). I 
claimed a minimum of 8 bits. Somewhere between 12 and 16 is more likely. 
However, with new ARIN proposals, we will see shorter shifts (yet still 
over 8 bit shifts) as it does nibble allocations for everything (pop 
assignments nibble aligned, ISP allocations nibble aligned, ISP to ISP 
reallocation policies). It treats utilization as a 75% bar with nibble 
alignments to allow for proper growth at the ISP level.

Why would a pop need to be nibble aligned?  Customers should be
nibble aligned as it requires a delegation in the DNS.  A pop doesn't
need a delegation in the DNS.

Mark
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka () isc org


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