I would be a bit nervous about dedicating another /3 for unproven
use. There's a risk of it ending up unusable like Class E. So
if we are going to do this, doing it inside 2000::/3 seems a
bit safer to me.
So what if we could say the use is simply to assign addresses out of this block
that stay relatively permanent to a device that sources packets from this
address.
The address has no dependency on the topology the device connects to, the
number of interfaces the device has connected to the network, or even if the
device is connected at all to the network.
So this proposal doesn't have to be associated with LISP or any other mechanism
being used. This block could be used today as simply a PI block if no new
mechanism is deployed. And if a sub-block of this prefix is used for LISP
purposes, then so be it.
And I don't think we have to jump in with 2 feet and allocate a very coarse
prefix for this.
Dino