Larry J. Blunk
ljb at merit.edu
Fri May 13 10:24:55 EDT 2005
On Fri, 2005-05-13 at 10:31 +0100, Michael.Dillon at radianz.com wrote:
> > o Increasing the HD ratio, or a flat utilization threshold fixes
> > any possible shortage. If that doesn't do it, /48 -> /56
> > would. The more I look at the numbers, the more convinced I
> > am that /48 should be left alone and a flat threshold be used
> > (perhaps 60%).
> I agree that the /48 --> /56 issue is definitely second priority.
> If we can solve the immediate problem by adjusting the HD ratio
> rules then we should limit current action to that area.
I think there are other reasons for considering /56's. Consider,
for example, university dorms rooms. Should each of them get a /48?
The University of Michigan has 5793 dorms and 1483 family housing
apartments (ref -- http://www.housing.umich.edu/general/factsheet.html).
You'd need a /35 at a minimum to give everyone a /48 and that wouldn't
leave much headroom or flexibility in addressing hierarchy.
Realistically, you probably want to assign a /32.
Merit provides Internet access for 13 universities and the State
of Michigan. Based on the above considerations, we asked for a /28
from ARIN (enough for a /32 for each university and the state). Our
application was denied, and we only received a /32. What size prefix
should allocate to the universities (ARIN suggested a /40)? What
prefix size should we advise them to assign to dorm rooms?
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