voluntary filtering of more specifics [Re: Geo pros and cons]

[Pekka Savola <pekkas@netcore.fi>]

One particular point..

On Wed, 2 Apr 2003, Iljitsch van Beijnum wrote:
> Since the scalability of geographical aggregation depends on the number 
> of internet users and the size of the aggregation areas, where each 
> aggregation area needs at least two interconnects, it would seem that 
> the scalability of geographical multihoming isn't a problem: more 
> multihomers means more routes in an area, but since more end-users 
> means more interconnects, the areas shrink. So the number of routes per 
> area should remain fairly constant.

.. depending on who is in charge of the aggregate and the routes, I've 
gotten a personal belief that if we build a system that allows more 
specific routes, we must have a system which can be used to block them 
too.

That is, e.g. longer prefixes from under current 2001 RIR allocations are 
a non-starter; they create a system where advertising more specifics is 
required for multihomers while giving away the control of more 
restrictions of more specifics.  "meant for longer prefixes of a certain 
length" allocations from a separate block would be completely different in 
this regard.

Similar seems to apply to geo-like approaches depending on geo-aggregates.  
Who (at the originating region) is creating the aggregate?  And more 
importantly, *why* should the sites or ISP's in the region be encouraged 
to *not* advertise their more specific geo prefix *anyway* (assuming the 
geo routing infrastructure might require that under some conditions)?  
There would seem to be a need for some control there, or all the traffic 
going through such big ISP's we could trust to do the right thing and not 
propagating the more specifics.

Otherwise we would end up with a routing table with *both* more specific
geo routes *and* the aggregates :-(

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings