proxy-aggregation commentary

[Geoff Huston]

At 3/21/01 07:07 AM, smd at clock.org wrote:

>1. "lazy" is unfair and was meant tongue-in-cheek, because gih clearly is not.
>     it was "australian" nonplural, not an attack on TELSTRA
>
>     it did provoke some thinking in his head though :-)
>
>2. that said, what this means it that downstreams of stupi WILL NOT SEE
>    the subnets of 192.36/16 iff the subnet passed through AS 1221
>
>    downstreams (if they are NOT in the AS SET) will see the aggregate
>    and non-AS 1221 more specifics

thanks Sean,


2. is a really interesting point. The intent of the slides (sent to
Abha - I can't web em up for a while) was to say that policies,
as expressed today in specific advertisements, do have a 'use by'
attribute, and that there is no point to splash local policies
globally, but local policies are also not just as close
as NO EXPORT, and are not an AS TTL.

The 'use by' is harder to express, but its attempting to say that
the specifics do NOT need to be global, but can be aggregated
into a larger generic policy at "some distance away'. All vague
terms I admit, but this example of yours shows that there are
good mechanmisms to remote absorb local policy. Now comes the
more interesting bit - is there a way for the local origin
AS to trigger this remote policy absorbtion through a community
attribute of some form or fashion, or through a similar signalling
mechanism.


i.e. good technique Sean, thanks for pointing it out. Now going
through my head is the question of how to work out how to use it
in a way that helps us learn about how to express policy within
the inter domain space. If we can do that we are well past simple
proxy aggregation and well toward a way of expressing policy as
a qualification on an underlying connectivity.

   Geoff