About address allocating

[Francis Dupont]

 In your previous mail you wrote:

   
   >   hi, I have the following questions about address allocating:
   >     I know SLA is /48, and interface ID should be 64 bits, 
   >   does it mean that the smallest unit when allocating address is /48?
   >   In other words, if I allocate a /48 to a large university, could I 
   >   allocate a /48 to four middle schools, thus each middle school gets
   >   an block less than /48, which is /50. Is this plan reasonable?
   >
   >=> we'd like to get a /48, ISPs would like to give a /64 to us:
   > - /48 seems a bit too large for a default allocation size
   > - /64 is unusable when you need subneting
   >then the current idea, as presented yesterday here in Budapest
   >at the RIPE meeting, is to introduce "small site" which get
   >/56 (on byte boundary, large enough for up to 256 subnetworks or
   >a few levels of hierarchy).
   >Then /56 will become the default allocation size in RIR
   >allocation & assignment document.
   
   	I'm not sure if introducing "small sites" is a good thing...
   	when we switch ISP and they force me to switch from /48 to /56,
   	renumber becomes very hard.
   
=> the idea is that it is easier for someone which needs a /48
to deal with its ISP than for a common customer to fight in order to
get a /48 because /64 is not enough: this is a compromise for common
customers (ie you at home, IIJlab is strong enough to get a /x with x <= 48).
I believe it is a good compromise...

Regards

Francis.Dupont@enst-bretagne.fr