I don't get the point of the /29 discussion anyways. It is based on the false assumption that we need to stretch the pool to eternity and beyond. We need to stretch the pool until we can test and establish IPv4 over IPv6 peering LANs. A /26 default is perfectly fine for that.
What's preventing "us" from testing and establishing this right now?
Is it a lack of impending doom?
Also, another argument I feel is missing is that 100% overprovisioning seems to be perhaps reasonable at very small sizes, but unreasonable at greater sizes.
Room for reasonable growth is not merely about percentages.
Over two thirds of current IXPs given the actual growth from 2019 to 2022, fit within a /27 with *some* overprovisioning.
Combined with the option to request a greater initial size, I'd argue that *if and only if* the point is to stretch this pool's lifespan, a /27 is both reasonably large as a minimum size, yet not too large.
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Jan