[address-policy-wg] IXP pool lower boundary of assignments

* Matthias Wichtlhuber

> Moreover, I have updated the analysis to include /29s (which I
> previously cut off). Only ~25% of all IXPs would fit into such a
> small peering LAN. Setting the default to /29 will likely cripple the
> growth of IXes. There is also no benefit in retaining these resources
> if they are needed.
> 
> https://github.com/mwichtlh/address-policy-wg

Thank you for updating! It is always nice to have real data to look at.

I think I disagree with your use of «only». 25% isn't «only» in my
opinion, that's a quite considerable share of the total. If I read your
report correctly, the group of IX-es that will manage comfortably with
a /29 is in fact the largest group of them all!

(Here I do say manage "comfortably" since your report state that it
assumes 100% oversubscription, which I take to mean that the IX-es in
each bracket can *at least* double their member count without running
out of addresses.)

Also I don't understand your «crippling the growth» concern. The 75% if
IX-es that need something bigger then a /29, they would of course get
something bigger – just like they do today, if they need something
bigger than a /24.

Has today's policy, where /24 is the default, «crippled» any IX from
growing past 254 connected members? If not, how exactly would a default
/29 policy «cripple» an IX from growing past 6 members, or a default
/28 «cripple» it from growing past 14 members for that matter?

Or to put it another way: if we change the default to /25 or /26 as you
propose, wouldn't that change – in the exact same way as for /29 –
«cripple the growth» of those IX-es past 126 or 62 connected members?
If so, how come that is OK, if it isn't OK for /29?

Tore