Re: [RRG] Geographic aggregation-based routing is at odds with reality

["William Herrin" <bill@herrin.us>]

On Tue, Jul 22, 2008 at 5:44 AM, Iljitsch van Beijnum
<iljitsch@muada.com> wrote:
> On 21 jul 2008, at 16:59, William Herrin wrote:
>
>>>> According to your algorithm, the nodes outside a block should
>>>> opportunistically aggregate any routes it can for that block.
>
>>> No, aggregation is local to an AS.
>
>> Then you only perform aggregation in origin-only ASes (like A, D, E
>> and H in the diagram) and don't attempt to aggregate in the others?
>
> No, of course not. Aggregation in origin-only ASes is not the main issue,
> because those ASes don't necessarily have to run default-free.
>
> The point is aggregation in the tier-1 service provider networks where
> default routes can't be used.

Then what exactly are you aggregating?

If you're aggregating routes in a tier-1 then the routes that tier-1
passes on to its neighbors have been aggregated.

If aggregation is local then you're not passing aggregated routes to
your neighbors.

What about your plan modifies these two statements so they're no
longer mutually exclusive?

Regards,
Bill Herrin

-- 
William D. Herrin ................ herrin@dirtside.com bill@herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

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