Re: [RRG] getting rid of longest match

[Per Heldal <heldal@eml.cc>]

On Tue, 2008-02-26 at 00:06 +0100, Iljitsch van Beijnum wrote:
> On 25 feb 2008, at 23:43, Scott Brim wrote:
> 
> >> What I'm thinking is that for any given part of the address space,  
> >> there would be a fixed prefix length. So for 192.0.0.0/8 /24, for  
> >> 64.0.0.0/8 /20, for 17.0.0.0/8 /8... So in theory, there would be  
> >> no overlap. There could still be if the filters weren't set up  
> >> properly, which would probably have to resolved when translating  
> >> the RIB into the FIB.
> 
> > Isn't this just what we did pre-CIDR?
> 
> Yes, except that it wouldn't be hardcoded into the IP stack but  
> enforced through filters. 

That  starts to sound a lot like a suggestion from Proteon related to
BGP-research in the early 90s. Their idea was that all IDRs would need
to form a "relationship" with all relevant address-authorities (now
registries) for the network within which it operates. For a DFZ-router
today that would translate into a private registry, all RIRs and IANA.
Via a simple protocol routers would be fed a list of address-blocks and
the corresponding smallest allocation block within. In today's network
that would enable dynamic rules that for example could block anything
smaller that RIR allocation-blocks globally, while permitting +n TE-bits
from neighbors. Although reasonable for recent (>2000) allocations it
may not be an answer for legacy-allocations ... and it only addresses a
small part of the problem.


//per



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