RE: what problem is solved by proscribing non-64 bit prefixes?

[<michael.dillon at bt.com>]

> Actually, you cannot just assign a /48 to each site.  The RIR 
> H-ratio requirements may make this infeasible.  Further, each 
> /48 (/56 for
> IANA) allocations must be registered with the RIR, which is 
> an administrate headache.  Finally, there is the issue of 
> reverse lookup registration for sites.  These are just the 
> policy issues.

I don't believe that /48 assignments have to be registered with
the RIR unless it is a situation where an ISP is assigning the
/48 to another entity. Within an enterprise, /48 assignments to
a site do not need any RIR interaction. In addition, if you
are a large organization, then the RIRs will give you a /32 ISP
allocation which should be enough forever, except for a few of
the very largest companies. Those companies should actually plan
ahead and get a bigger than /32 allocation to begin with. The 
H-ratio should only ever be an issue for ISPs since their networks
are expected to grow continuously and eventually outgrow any allocation.

However, RIR rules are set by the networking community collectively
and bad rules can be changed.

--Michael Dillon
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