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Re: 90 IPv6 sub-TLA allocations made

  • To: "Dave Pratt" < >
    "Peter Willis" < >
  • From: "Stephen Burley" < >
  • Date: Wed, 15 Aug 2001 10:30:12 +0100
  • Cc: "lir-wg" < >
    "ipv6-wg" < >

This is not including the needed aggregation for multi-national registries,
its fine for a single network but, still would tie your hands when
sub-allocating to multiple LIR's.

Regards
Stephen Burley
UUNET EMEA Hostmaster


> Colleagues,
>
> I've just done some calculations that shows the maximum theoritical
> utilisation that can be achieved is 75% whilst maintaining the minimum
size of
> routing table. That is if you take a large number of subnets, each subnet
>  containing a random number of hosts, and assign to each subnet the
nearest
>  power of 2 larger than the number of hosts, the utilisation you get is
75%.
>
> This is a 75% utilisation per level of network hierarchy.
>
> So if we assume 3 levels of network hierarchy and each level doing perfect
>  routing aggregation and perfect address allocation we will get an overall
>   utilisation of
>  0.75^3 = 0.422 == 42% overall utilisation for the TLA.
>
> I'd like to bet that if we have a network with enough hosts to justify 64
bits
> of address space it'll also be large enough to require more than 3 levels
of
> network hierarchy. Any requirements to get high address space utilisation
out
> of IPv6 can simply be demonstrated to lack scaling qualities.
>
> Regards,
>
>
> --------------------------------------------------------------------------
-----
> Peter Willis             | E-mail: peter.j.willis@localhost
> IP Technology Strategist            | Phone:  01473 645178 Fax: 01473
644506
> BTexact Technologies CTO            |
> --------------------------------------------------------------------------
-----
>
>





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