[address-policy-wg] 2023-01 - Clarification about the utilisation requirement for IXPs requesting an assignment larger a /24

Dear colleagues,

Reading the comments on this list, I would like to provide some 
clarification.

If the proposal is accepted, it would only change the initial assignment 
size and offer the option to "jump" directly to a /24 when at least 33 
addresses are in use. The utilisation requirements for IXPs requesting 
assignments larger than a /24 would remain unchanged.

When receiving requests for more than a /24, the RIPE NCC checks that 
the IXP will need more than 50% of the assignment within one year. If 
their growth rate is too slow and we expect that it will take more than 
a year to exceed that utilisation threshold, we suggest that they 
postpone their request.

Kind regards,
Marco Schmidt
Manager Registration Services
RIPE NCC

On 08/05/2023 15:56, Steven Bakker via address-policy-wg wrote:
> 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
>