10/8 used to be a DoD address block, but it was also used exclusively in their blacker networks and similar non-connected infrastructure. The result is that 10/8 was opened up for others to use as well. Could we do similar with 7/8?
What problem would that solve instead of reducing a wee tiny bit the collisions that might occur? Large networks are currently already established and renumbering them from 10.0.0.0/8 to 7.0.0.0/8 would still be renumbering.
Renumbering? Was somebody discussing renumbering? The problem that releasing 7/8 would solve is that IANA could allocate it to an RIR and the RIR could allocate it to customers. Given the finite nature of the IPv4 space, it is a bad thing to lock away address blocks that could be used by others.
Also note that Fastweb in Italy is already using 7.0.0.0/8 inside their network for their customers, who sit behind a NAT.
And I know a company that has been using 1/8, 2/8, 3/8, 4/8, 5/8, 6/8, 7/8 and 8/8 for many years, also behind NAT or on non-Internet connected networks. But that is not what I am talking about here. In fact, I would like to see a mechanism where large address blocks used primarily in a single geographic area, are made available for reuse in other geographic areas. This would extend the lifetime of IPv4. --Michael Dillon