when & how could policy be changed
At 22:59 01-07-97 -0500, you wrote:
>In message <18.104.22.168.19970701214734.00714c18 at pop.srv.paranet.com>, Stephen
>>The proposal was to allocate a fixed number of PI /20 blocks which would be
>>specifically for use by multihomed providers that didn't qualify for a /19
>>(or shorter) under RFC 2050. This will not double the total table size,
>>only increase it by 4k routes in the short term; hopefully, in the long
>>term it would reduce the number of more-specifics advertised out of the
>>large ISPs' PA blocks, having a net REDUCTION in the routing table size.
>This seems fairly problematic to me. Based on previous rushes on
>the registries (Can you said Internic, before Sean's /19 filter?), I would
>expect to see this resource consumed very fast, without substanitally
>impacting the base perceived need.
My history maybe be a bit lacking, but wasn't Sean's /19 filter to cut out
the more-specifics being advertised out of the large ISPs' PA blocks? I
don't believe this had anything to do with a rush on the InterNIC.
The rush on the InterNIC for Class B networks was the cause of CIDR
deployment, and is relevant in that we have learned the need for
restricting who gets allocations of what size.
>We would defenitely require some type of assurance of a net reduction
>in table size,
Take a look at my suggested requirements in another thread.
>but this assumes that these small customers would be
>allowed to de-aggregated from their PA space, which in a large number
>of cases is contractlly disallowed currently. So I still don't see a
It's not contractually disallowed in any case I've seen. You can advertise
a Sprint PA block more-specific to MCI easily (and Sprint will cooperate by
passing on your more-specific to other AS's); this is the exact problem we
intend to tackle.
>I'd like to seem some real world numbers based on multihomed ASs
>announcing /20s or smaller that aren't aggregated currently.
A number of people are working on producing numbers.
>>N will remain roughly constant, since we are merely switching PA route(s)
>>for an equal or slightly shorter PI route. M will remain constant, since
>>the AS's in question are already advertising routes on the net.
>M increase with the number of multihomed customers also, since each route
>appears in two or more views. Essentlially now a /19 is required to
>multihome via BGP and have global reachablity. This reduces the
>number of possible multihome sites.
No, anyone can multihome now who wants to, it's just very painful if you're
using PA addresses.