Supernet block sizes - recommendations?

Marten Terpstra Marten.Terpstra at
Thu May 13 12:19:11 UTC 1993

 peter at writes:
 * Bill,
 * You should probably forward  your suggestion for encouraging people to get 
 * their addresses from CIDR blocks to the NIC and to the IANA.

We feel the same way. We delegate maximum of 1 block of 256 class Cs at a
time to service providers and other registries. We keep more blocks reserved
for them based on their 2 year class C usage estimate, but do not hand all
these over at once. If registries get requests for large amounts of address
space (typically 256 Class Cs or more) they usually send the customer
directly to us, or we provide an extra block to the registry to fulfill the
customer's request, not necessarily in the "bigger" supernet block of the

I think in the US, a good interaction between the service providers and
IANA/NIC could result in a similar scheme, which has worked quite well in
Europe so far.


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