Aris Lambrianidis wrote on 04/06/2019 18:03:
Consulting the PCH IXP directory as Nick did earlier (as well as the
Euro-IX one), I think it is also reasonable to say that
allocating a /24 is ambitious for the overwhelming majority of cases.
Only 64 of listed IXPs have equal to, or more than, 100 participants,
out of 958 IXPs, or about 6.6%.
In this light, perhaps the default allocation discussed in 6.1.4 should
go down to a /25.
/25 is too small, even for smaller IXPs.
~400-500 of the entries in the PCH IXP directory are defunct. For the
remainder, the participant numbers are inaccurate, mostly on the low
side. A figure of about 500 active IXPs is largely corroborated by the
IXP DB (650 entries, with some effectively defunct).
The figure you need to look at is 50% usage rather than 100% usage. If
you pin the assignment size to /25, then 50% of /25 is 64 participants,
i.e. about ~20-25% of IXPs, not 6.6%.
The current run-out rate for the RIPE pool is about 15k addresses per
day. This means that a /16 is 4 days worth of allocations at the
current rate. A /16 pool gives adequate breathing room for core
internet infrastructure, with a /24 assignment size.
The central question of this policy update is not the assignment size
for IXPs, but whether it's worth investing 4 days out of 30 years worth
of allocations in order to provide important flexibility for the
internet core in the future. I'm inclined to think it is.
Nick
