I am still not convinced this is something we should doing. That being said:

On Wed, Apr 16, 2014 at 1:06 PM, Sander Steffann <sander@steffann.nl> wrote:

This doesn't feel right. If we make a policy to give more IPv4 addresses to the LIRs that only have one /22 then it should be:
- equal for all of them

Arguably, anyone with more than a /22 is in a better position, already. Allowing LIRs with less than one /21 to top up to a /21 and giving everyone else that one last-/8 /22 would be the "most equal" (for some value of).

I.e. in times of scarcity, the absolute number, and not relative gains, would come nearest to "fairness" (for some value of).

The last /8 could be used for the initial /22, the returned addresses for the second one; optionally with NCC-internal accounting so LIRs can get one single continuous /21. That way, last-/8 would remain in effect.

- sustainable for a long time

Well... no. It would only drag out v6 adoption a little more while admittedly easing the pain of new LIRs. Until they run out again and we restart the same discussion for /20.

And if it turns out that we _need_ more than the absolute reserve of IPv4, we will have less wiggle room.

Richard