The MPLS WG Archive

[Eric Osborne <eosborne@cisco.com>]

If MPLS breaks, and routing isn't available, then routing wouldn't
occur. :)

Having IP available as a backup path to MPLS is a nice
belt-and-suspenders idea, but there are some services (MPLS VPNs,
circuit transport, etc) that have no way to fall back to a non-MPLS
path.  



eric


On Thu, Sep 28, 2000 at 01:18:27PM -0500, Chris Flores wrote:
> Interesting, then I have the following question. Let's say the transit
> backbone consists of a 3 level hierarchy - core, distribution and access.
> BGP is configured such that the access (or edge) routers are route reflector
> clients of the distribution routers. Furthermore, the distribution routers
> are route reflector clients of the core routers. As Michel Redondo Ferrero
> has stated, MPLS VPNs originate and terminate on the access or edge of the
> network (in his scenario). Why would you turn off BGP on the core routers?
> What if MPLS breaks or fails for any reason (i.e. software bug). Then, how
> would routing occur?
> 
> Regards.
> 
> chris
> 
> -----Original Message-----
> From: Javier Antich [mailto:javier.antich@telindus.es]
> Sent: Thursday, September 28, 2000 11:28 AM
> To: Michel Redondo Ferrero
> Cc: mpls@UU.NET
> Subject: RE: MPLS/BGP routing question
> 
> 
> Core Routers do not need to run BGP because they, in practice don't take
> routing decisions with user traffic (I mean traffic comming or going to
> Internet), they just switch frames based on their MPLS label. BGP decissions
> are made at the edge and packets sent to the BGP next hop through the
> corresponding MPLS LSP.
> 
> 
> 
> 
> 
> Visite nuestro web: http://www.kerndatanet.com/
> <http://www.kerndatanet.com/> 
>                                http://www.telindus.es
> _________________________________________________________________________
> Javier Antich Romaguera.                          KERN DATANET -TELINDUS
> ESPAÑA
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> 
> 
> 
> 
> 	-----Mensaje original-----
> 	De:	Michel Redondo Ferrero [SMTP:mredondo@idecnet.com]
> 	Enviado el:	jueves 28 de septiembre de 2000 8:26
> 	Para:	mpls@UU.NET
> 	Asunto:	MPLS/BGP routing question
> 
> 	Hi,
> 
> 	Considering the next scenario:
> 
> 	-Core and Border routers running IS-IS, MPLS
> 	-VPNs configured in Border routers using BGP/MPLS
> 	-Border routers running BGP with full-routing
> 
> 	The question:
> 	Do Core routers need to run BGP? Is IS-IS enough?
> 
> 	Thanks in advance for your answers.
> 
> 	Michel Redondo Ferrero