RE: selective auto-aggregation

["McBurnett, Jim" <jmcburnett () msmgmt com>]

Only 1 question:
What about the companies that have a /24 out of the /20 0r /21 that are multi-homed?
If the route rules are not carefully prepared the multi-homed customer then might be single-homed and tied to the 
upstream they got the IP's from.

Thoughts?

Jim

> -----Original Message-----
> From: bdragon () gweep net [mailto:bdragon () gweep net]
> Sent: Thursday, April 17, 2003 3:56 PM
> To: nanog () merit edu
> Subject: selective auto-aggregation
>
>
>
> I believe we're losing the aggregation war. More and more entities are
> deaggregating, and not announcing their largest aggregates which makes
> prefix-length filtering less effective.
>
> I'ld like to propose the concept of selective aggregation, whereby
> a router can be configured to aggregate based upon rules.
>
> For example, if an RIR allocation boundary for a particular /8 is
> /21, that routes which are longer than /21 could be aggregated to
> /21 rather than discarded. Obviously, this would only be effective
> facing one's transit, since aggregating a peer would violate most
> peering agreements. In transit-free networks, this functionality would
> not be useful.
>
> Similarly, the ability to auto-aggregate contiguous networks originated
> by the same AS, which could be applied even to routes with lengths
> shorter than an RIR boundary. This functionality could be useful
> facing ones peers.
>
> This type of thing would need to be selective, since permitted
> deaggregation (no-export tagged routes with meaningful MEDs) can
> still be useful between entities which agree to such things.
>
> If we can, I'ld like to avoid a holy war on whether deaggregating
> is someone's god given right, and stick to the premise that there
> are networks who will enforce aggregation policies, and want to do so
> in the most effective manner possible.