Subject: RE: Proxy: comments on section 9.1.3

From: "Abarbanel, Benjamin" <[email-masked]>
Date: Fri, 6 Sep 2002 10:26:59 -0400

Mathew:

> >
> >I'm looking for clarification to wording in section 9.1.3 
> Phase 3: Route
> >Dessemination of draft-ietf-idr-bgp4-17.txt.
> >
> >My understanding is that a BGP route should not be 
> advertised to a peer if
> >that route is not also in the Routing Table (e.g. FIB).  I 
> was looking for
> >wording to support this, but am now starting to second guess myself.
> >

What about the case where the best BGP route for a given destination is
rejected/
preempted from the routing table by a higher preferenced IGP, Static, etc.,
route which is really used for forwarding?

Somewhere in section 9.1.x, Do we want to mention the fact that the best 
Loc-RIB BGP route for a given destination is still advertised to outgoing 
peers via the Adj-RIB-out after it passes the outbound policy filtering,
even though it is not really used for forwarding?

Ben

---

From: "'Mathew Richardson'" <[email-masked]>
Date: Fri, 6 Sep 2002 10:34:22 -0400

> Abarbanel, Benjamin <[email-masked]> [Fri, Sep 06, 2002 at 10:26:59AM -0400]:
>Mathew:
>
> 
>> >

This route would have to be in the Loc-RIB, and would replace all other
routes in the Loc-RIB.  Whether this actually happens or not is a matter
of local-policy.

>even though it is not really used for forwarding?

<snip>

You're talking about the case where a BGP route to some destination D
has been installed in the Loc-RIB, but no route to destination D has been
added to the forwarding table?  I'm not sure we want to elaborate on that
case, except, perhaps, to disallow it.

mrr

---

From: Jeffrey Haas <[email-masked]>
Date: Fri, 6 Sep 2002 10:39:52 -0400

> case, except, perhaps, to disallow it.

Route servers.
Also, route reflectors do not necessarily need to be in the forwarding
path of the routes they are reflecting and thus don't necessarily
need any routes installed in the FIB.

-- 
Jeff Haas 
NextHop Technologies

---

From: "'Mathew Richardson'" <[email-masked]>
Date: Fri, 6 Sep 2002 10:41:38 -0400

> Jeffrey Haas <[email-masked]> [Fri, Sep 06, 2002 at 10:39:52AM -0400]:

<snip>

And what do either of these have to do with the base BGP spec?

mrr

---

From: Jeffrey Haas <[email-masked]>
Date: Fri, 6 Sep 2002 10:49:36 -0400

> And what do either of these have to do with the base BGP spec?

Adding language that specifically forbidding adding routes to Loc-Rib
when they wouldn't be added to the FIB would preclude some forms
of route concentrators.  I don't think we really want to do that.

-- 
Jeff Haas 
NextHop Technologies