Subject: RV: Does MPLS Require L3 Routing Table ?

From: Javier Antich <[email-masked]>
Date: Thu, 19 Apr 2001 10:55:31 +0200

Well, I have been following the thread and I have not seen one basic thing.
Of course you need IP routing table if you run MPLS in and IP network, but,
you do not need to have the full Internet routing table in all the routers.
You can remove BGP from the core so that BGP decisions and Next-hop BGP
resolutions are done at the edge and the appropriate label is selected for
reaching the right exit point from the cloud. Then, you need IP routing
table, but if it is a core router and it is an Internet environment, the
routing table can be much smaller than it would be if you were not running
MPLS.

Sorry if someone received the mail several times, I am having some problems
with my subscription.
                                          ^   ^
==============ooo====(.)v(.)====ooo=====
Javier Antich Romaguera
Network Consultant
---------------------------------------------------------------------------
TELINDUS 
Pza. Ciudad de Viena, 6-2º
28040 Madrid 
---------------------------------------------------------------------------
[email-masked]
tel: +34 91 456 00 08
fax: +34 91 536 10 74
---------------------------------------------------------------------------
For more information about our products and services,
please visit our website http://www.telindus.com
---------------------------------------------------------------------------
Full connectivity & mobility
==================ooo0===0ooo========

> 	-----Mensaje original-----
> 	De:	Rajesh P Jain [SMTP:[email-masked]]
> 	Enviado el:	viernes 13 de abril de 2001 10:16
> 	Para:	Bharti Batra; [email-masked]
> 	Asunto:	Re: Does MPLS Require L3 Routing Table ?
> 
> 	"Hello",
> 	                        Thanks for the response.
> 	 
> 	                        Well, if it requires L3 Routing table to
> build up the Label information, then what is the advantage of MPLS???
> Well, Anyhow, it will require the building of L3 Routing Table (May be
> through RIP/OSPF/BGP etc), then Lable info can be formed by using only L3.
> So, Anyhow, MPLS is dependent on L3, please explain me what is the
> advantage of using MPLS (in terms of efficiency and speed switching of the
> packets).
> 	 
> 	With Regards
> 	                    Rajesh P Jain
> 
> 		----- Original Message ----- 
> 		From: Bharti Batra <mailto:[email-masked]> 
> 		To: Rajesh P Jain <mailto:[email-masked]> ; [email-masked]
> <mailto:[email-masked]> 
> 		Sent: Friday, April 13, 2001 1:09 PM
> 		Subject: Re: Does MPLS Require L3 Routing Table ?
> 
> 		Hi !
> 		 
> 		Yes. LDP needs IP routing table to find out the route
> towards the egress router to setup the LSP. LDP sends the LSP setup
> request message along this path.
> 		 
> 		Regds,
> 		Bharti
> 
> 			----- Original Message ----- 
> 			From: Rajesh P Jain <mailto:[email-masked]> 
> 			To: [email-masked] <mailto:[email-masked]> 
> 			Sent: Friday, April 13, 2001 12:52 PM
> 			Subject: Does MPLS Require L3 Routing Table ?
> 
> 			"Hello", List,
> 			                    Well, I am very new to the MPLS
> domain. I just wanted to check out whether MPLS domain neccesarily require
> the L3 Routing Table (Maybe IP Routing Table) to build up it's label
> (using the LDP Protocol). Or the LDP will take care of building the label
> information automatically without the L3 Routing information?
> 			 
> 			TIA
> 			        Rajesh P Jain
>