Given a site that has a need for a certain number of addresses, but probably will never need additional networks to fill out a power of two allocation. Should we allocate the larger block to the site anyway to reduce the size of the routing table, or should we allocate two CIDR blocks?
For example, if a site will only realisticly need 6 class C's, should we allocate a block of 8, or a block of four and a block of two.
Given that the immediate threat is the growth of routing tables, not IP address space exhaustion it's better to allocate powers of 2-sized blocks and announce only one route. The IP space overhead is about 30% but routing table savings are at least 50%. Actually, CIDR allocation helps to slow down IP address allocation by providing most of organizations an alternative to class B. We have sliced an eqivalent of 4 calss B to about 100 customers! So the 2008 doomsday estimate may be kind of pessimistic :-) --vadim