as-out metrics

  > as-out describes how an AS export routes including what routes to export
  > and what metric it announce them. 

preference!=metric

preference is a static preference, protocol independent.
It describes routing policy in a clearly defined way.

	Understand.
	But what is the problem to have AS to express how they
	export the routes i.e. to express the exporting metrics ?

metric is protocol specific. It *may* affect routing policy 
in some way.

	Because it may affect routing policy, it is useful for
	AS to regist it.  After all, we are registing routing
	policy.
	 

  > So it actually make as-out more symtric to as-in by adding export
  > metric.  And it also fits the definition of as-out. 

Symmetry for symmetry's sake is not necessarily a good idea.

	But you were arguing that we break the symtricy of as-in and
	as-out by putting metric in? I am just indicating that it
	does not.
  
Different things should go in different places.
Also what is so special about BGP metrics.
What metrics are in IDRP?

	It does not matter if it is bgp metric or other metric.
	What matters is the metric people use to export routes.
	It is not just bgp specific.


  > Create a new attribute of bgp_metric like you suggested has someside
  > that is:
  > 
  > ASs have to repeat what described in as-out in order just to put metric
  > with the different set of routes it advertised.  It is really redundant
  > to as-out. 

Agreed. 
How widely is it really used?
Is the metric maybe often defined per peer rather than per peerXAS?

	AS which hear the same routes from different ASs or 
	AS which advertise routes to different ASs or one AS at different
	connection points all has possiability to do so.  we shoul have
	a scalable way for them to express that. 
Daniel


						--Jessica




-------- Logged at  Mon May 2 14:26:18 MET DST 1994  ---------