- that less than 50% of the v4 space is currently routed. scarcity will presumably cause these non-routed blocks to be: :- used and routes :- reclaimed and reassigned :- sold on
Uh, no. Just because the address space is not visible in the public Internet's default free zone does not mean that it is sitting on a shelf in a dusty warehouse. Most of that space is actively in use by organizations who explicitly want an IP internetwork that is disconnected from the Internet, or by organizations who can achieve multihomed connectivity from two upstreams without needing their routes to be propogated between those upstreams. This kind of thing happens way out at the edges of the network, far from the core, where two upstreams maintain peering links (possible at a local Internet exchanges). So to sum up. They are used and routed already. They cannot be reclaimed since they are fully justified. And they can't be sold because they are used for mission critical networks.
- that much of the space in use within organisations could be optimised :- mop up unused gaps in subnet
This will cause routing table scaling problems inside organizations, exacerbated by the greater amount of legacy hardware found in such environments. --Michael Dillon