Re: WG next steps

[Iljitsch van Beijnum <iljitsch@muada.com>]

On Mon, 18 Nov 2002, Andrew Partan wrote:

> I'll try to explain this again.

> I'm a large provider; I'm connected to two geo areas - A and B.
> Not everyone in area A is my customer.
> At B I connect to another provider.
> What routes to I announce to that other provider about area A?
> If I announce just my customers' routes, then aggregation is dead.
> If I announce just the area A aggregate, then I am giving free transit
> to everyone in area A.
> Neither one flys.

You announce your customers. You don't get to aggregate those. However,
you only accept routes for people in the A and B regions from your
peers. If you have a packet for someone in region C you route it towards
the router inside your network that has information about region C.
Conversely, in region C there are only aggregates towards A and B in the
routing tables.

This limits the aggregation to how many routers with good
interconnection you have, but not necessarily to the number of
interconnect locations = you can solve the scalability problem by
throwing hardware at it, which is not great but still much, much better
than not being able to solve it at all, so I think it is a reasonable
short term solution.