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Using IPv6 with prefixes shorter than a /64 on a LAN
In message <4D4CA1B1.5060002 at brightok.net>, Jack Bates writes:
> On 2/4/2011 6:45 PM, Mark Andrews wrote:
> > I used to work for CSIRO. Their /16's which were got back in the
> > late 80's will now be /48's.
> That's why I didn't try doing any adjustments of X is the new /32. The
> whole paradigm changes.
So why the ~!#! are you insisting on comparing IPv4 allocations with IPv6
> Many ISPs devote large amounts of space to
> single corporate network sites. Those sites will now have a single /48.
> On the other hand, we currently give /32 to residential customers. They
> also are getting a /48.
> Which is why the only way to consider address usage from an ISP and RIR
> perspective is by how it is handed to a standard ISP of a given size.
There are two sizes. Those that fit into a /32 and those that don't.
The latter ones have to justify their allocations.
> Originally, ARIN was being overly restrictive and it was "/32 for every
> ISP". They have loosened up, and will continue to do so (including ISP
> to ISP) as future proposals come to fruition. So from an ISP
> perspective, you have to consider your total IPv6 allocation size
> (within the first 32 bits of IPv6) in comparison to your total IPv4
> allocations summed.
No. You need to compare it to the number of customer sites. If you
have 1 customer with wires going to two locations thats two /48's.
> From what I can tell, on average, all ISPs are shifting between 8 and
> 16 bits to the right from their total IPv4 size depending on their
> primary customer type (residential ISPs shift less than ISPs that
> primarily only service corporations).
Residential ISPs shift 16 bits (48-32=16). You shift less if you
have less than 64000 customers sites and don't get address space
from a larger ISP. Commercial ISPs shift more as what was multiple
address at one sites becomes 1 /48.
Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117,
Australia PHONE: +61 2 9871 4742 INTERNET: marka at isc.org