Re: IP network address assignments/allocations information?

[Christian Huitema <huitema at research.telcordia.com>]

At 03:47 PM 12/9/99 +0100, Sean Doran wrote:

>Alternatively -- if we take Harald Alvestrand's numbers,
>and assume everyone who wants one gets an IPv6 /48,
>leaving 16 bits for subnetting before the "flat space" --
>can we try to quantify the consumption of critical
>resources in routers with this as an explicit goal?

Sean, the appropriate answer to your question is RTFM (as in, read the
manual.) The top 48 bits of IPv6 addresses are anything but flat. The flat
space is initially limited to the top 16 bits, 3 of which are used as a
format prefix, leaving a "flat space" table size of 8K entries. These
entries are supposed to be assigned to "top level" providers -- the
equivalent of v4's default-free ISPs. There is indeed a concern that 8K may
not be enough in the long run, which has lead to place the next 8 bits in
reserve. Each of these "top level" prefixes thus contains 24 bits of
address space for organization or delegation by the provider. 
-- Christian Huitema