[ppml] [narten at us.ibm.com: PI addressing in IPv6 advances in ARIN]

[Kevin Loch]

Christopher Morrow wrote:
> you have some basis for this? I don't have that same faith... I think
> that quite quickly every entity that has ipv4 space will have ipv6
> space in some PI fashion (if they have ipv4 PI space) and we'll all be
> stuck routing that and more from now until eternity. That will
> effectively double the current route table, which on much of the
> deployed networks isn't such a good plan.

While you make a good point about routes being around forever,
I don't think it will double route tables.

data from cidr-report.org:

Current prefix/AS ratio in IPv4:  8.4:1
Current prefix/AS ratio in IPv6:  1.2:1

If every AS participating in IPv4 (22,000) also participated
in IPv6 we might expect something closer to 27,000 v6 routes
instead of 182,000.

Why is the ratio so high in IPv4?  If I'm reading the report
properly about 4.2 prefixes/AS are due to deaggregation and
the remaining 4.2 are due to "slow start" assignment policies.

The generous minimums and reserved bits in v6 should
eliminate the "slow start" factor.   Separating PI space from
ISP space in the beginning can help reduce the deaggregation
factor if people filter out /48's by assignment range.  That
is highly recommended as there are at least 65,000 /48's in each
ISP allocation.

- Kevin