Subject: draft-ietf-l3vpn-2547bis-mcast-bgp-06 section 11.4

From: "NAPIERALA, MARIA H, ATTLABS" <[email-masked]>
Date: Wed, 8 Apr 2009 14:51:13 -0400

Question on section 11.4 of draft-ietf-l3vpn-2547bis-mcast-bgp-06
<http://tools.ietf.org/html/draft-ietf-l3vpn-2547bis-mcast-bgp-06.txt> :

How does the following (quote from section 11.4):

   "To further reduce the routing churn due to C-multicast routes
changes
   a Route Reflector that re-advertises a C-multicast route SHOULD set
   the Next Hop field of the MP_REACH_NLRI attribute of the route to an
   IP address of the Route Reflector. Likewise, an ASBR that re-
   advertises a C-multicast route SHOULD set the Next Hop field of the
   MP_REACH_NLRI attribute of the route to an IP address of the ASBR.

reduces route churn? 

Maria

---

From: Yakov Rekhter <[email-masked]>
Date: Wed, 8 Apr 2009 11:56:54 -0700

Maria,

>    "To further reduce the routing churn due to C-multicast routes changes

By aggregating C-multicast routes.

Yakov.

---

From: "NAPIERALA, MARIA H, ATTLABS" <[email-masked]>
Date: Wed, 8 Apr 2009 15:00:08 -0400

What does it mean "aggregating C-multicast routes"?

Maria

> -----Original Message-----
> From: Yakov Rekhter [mailto:[email-masked]]
> Sent: Wednesday, April 08, 2009 2:57 PM
> To: NAPIERALA, MARIA H, ATTLABS
> Cc: L3VPN
> Subject: Re: draft-ietf-l3vpn-2547bis-mcast-bgp-06 section 11.4
> 
> Maria,
>

---

From: Robert Raszuk <[email-masked]>
Date: Wed, 08 Apr 2009 13:26:33 -0700

Hi Yakov,

Do you mean that by aggregation of C-multicast routes that you are going 
to propose modification to SAFI independent route reflector code which 
today does advertise the best path among received for a given net 
regardless of the next hop policy ?

Thx,
R.

---

From: Yakov Rekhter <[email-masked]>
Date: Tue, 28 Apr 2009 14:37:14 -0700

Maria,

Maria:  How does the following (quote from section 11.4):
Maria:
Maria:   To further reduce the routing churn due to C-multicast routes changes
Maria:   a Route Reflector that re-advertises a C-multicast route SHOULD set
Maria:   the Next Hop field of the MP_REACH_NLRI attribute of the route to an
Maria:   IP address of the Route Reflector. Likewise, an ASBR that re-
Maria:   advertises a C-multicast route SHOULD set the Next Hop field of the
Maria:   MP_REACH_NLRI attribute of the route to an IP address of the ASBR.
Maria:
Maria:  reduces route churn?

Yakov: By aggregating C-multicast routes.

Maria: What does it mean "aggregating C-multicast routes"?

Since in the context of this document C-multicast routes are carried
in BGP, it should be abundantly clear that in the context of this
document "aggregating C-multicast routes" means "aggregating BGP
routes". The term "aggregating BGP routes" is covered in rfc4271
(BGP-4) section 9.2.2.2.

Yakov.

---

From: Robert Raszuk <[email-masked]>
Date: Tue, 28 Apr 2009 15:10:59 -0700

Hi Yakov,

 > routes". The term "aggregating BGP routes" is covered in rfc4271

You are incorrect about "abundantly clear" part.

The section 9 of base BGP spec RFC4271 as well as section 8 of RFC4456 
describing BGP route reflection behavior has been modified between lines 
to fit your new model of "C-multicast routes aggregation" by the route 
reflector. [Some of the details are listed in my former mail to this WG].

Those modifications to standard BGP behavior (as per the above RFCs) has 
not been explained to the WG and before we proceed with this draft any 
further I would request that such omission and changes to BGP will be 
addressed by new document in IDR WG proposing new model of BGP route 
reflection for the purpose of reflecting and aggregating C-multicast routes.

Cheers,
R.

---

From: "NAPIERALA, MARIA H, ATTLABS" <[email-masked]>
Date: Wed, 29 Apr 2009 08:16:08 -0400

Yakov,

> routes". The term "aggregating BGP routes" is covered in rfc4271

Since the "aggregation" takes place on the RR, could clarify what is the
ORIGINATOR_ID of those "aggregated" routes? 

Thanks.

Maria