On Thu, 2023-05-04 at 06:21 +0000, Matthias Wichtlhuber via address- policy-wg wrote:
The problems in section 5 can be fixed easily, but it depends on how the authors want to handle assignment upgrades / renumberings. I'd suggest either dropping the 1Y utilisation requirement to e.g. 40%, or else that if you reach e.g. 80% current usage, you qualify to receive an assignment of 2x the current, up to /22. Those figures are plucked out of the air btw. The point with them is that they are not 50%, which is obviously a magic number when the natural increase of assignment size would be to double the size of the block.
The goal of this part is to minimize renumberings while avoiding greedy requests. Dropping the one year requirement to 40% is reasonable if you think 50% is too harsh ("magic numbers"). We can incorporate this change.
I believe that what Nick was getting at was that 50% is "magic" in the sense that it creates a problem: * a /24 has 254 usable addresses. * a /23 has 510 usable addresses -> half of that is 255. So, suppose you have used 230 addresses out of your /24. You apply for and get a /23 and happily renumber. Then, after one year, you have used 254 addresses. This is less than half of the /23 (510/2 = 255), so according to the rules you'd have to downgrade back to a /24 again. You can now no longer grow, unless you immediately apply for a /23 again. So we either live with this "bug" and trust that whoever has to perform evaluation is "reasonable", or we find a numbers that don't cause these kind of edge cases. Cheers, Steven