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

[Geoff Huston]

At 04:31 PM 17/04/2006, Kevin Loch wrote:
>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

agreed.



>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.


Yes - I'd agree with this - around one half of the Ipv4 advertisements are 
more specifics of a covering aggregate, so of the 8.4 prefix advertisements 
per originating AS, one half of these advertisements are more specifics of 
a covering aggregate.  The remaining 4.2 prefixes are a combination of slow 
start and swamp space, so its not entirely correct to attribute the entire 
number to slow start assignment policies.

   regards,

     Geoff