[arin-ppml] 2010-8: Rework of IPv6 assignment criteria

[Owen DeLong]

On Sep 20, 2010, at 9:13 AM, Leo Vegoda wrote:

> On 18 Sep 2010, at 5:00, David Farmer wrote:
> 
> [...]
> 
>> Furthermore, very large hierarchical end-user networks, especially for a 
>> large multinational corporation, are not precluded from considering 
>> themselves as an ISP or LIR, and then starting with a /32 and being able 
>> to avail themselves of HD-Ratio.  That might be more appropriate anyway, 
>> the networks for large multinational corporation with many independent 
>> business units, probably have much more in common with ISPs then the 
>> majority of other end-user networks.
> 
> I think this would resolve the problem for larger, more complex end user networks. 
> 
> Leo

I think the simpler (and much cheaper for the organization) approach
would be to realize that the "Large Complex" networks are almost never
implemented in a single building.

End user networks within a given structure tend to have very few
layers, often consisting of:

workgroup->floor->datacenter->Building exit

Rarely does it get to more layers than that and moving prefixes
around within the structure is relatively free form. There is usually
very little loss of prefix space due to aggregation at any of those
levels because within a building, aggregation is usually regarded
as meaningless.

Since EACH structure gets at least a /48 and you are guaranteed
a certain amount of headroom in the number of /48s you get if 
you have more than a single building, I simply don't see where this
could become an issue.

Leo, can you provide a concrete counter-example?

Owen