label allocation is  significent only between two  routers

FEC simple means destinations prefixes .

egress router  assigns  labels  randomly  ...let say  he has 10.0.0.0/24  ,
11.00.0.0/24... and allocates   20 and 21 respectively .

via LDP  he  (R2)   sends his mappings  to its downstreem peer (R1).
saying if you  recieve any packet destined to 10.0.0.0 send me labeled
packet with label 20.

now he has  incomming label   20..mapped to   10.0.0.0 .......later he
hears  a mapping from his (R3)  uptreem peer  mapping  (next hop)  ..let
say  again  20  . this completes his binding.

---10.0.0.0    incommng  20  <=SWAPPED WITH =>    20 ---




On Sat, Apr 13, 2013 at 10:45 AM, bitje <[email protected]> wrote:

> Through L(abel)D(istribution)P(rotocol) which is enabled when you
> issue the "mpls ip" command.
>
> On Sat, Apr 13, 2013 at 01:11:21PM +0530, vishal bhugra wrote:
> >Hello experts
> >
> >I was reading MPLS Fundamental book. In Chapter 2 page 36, they have
> >mentioned that MPLS Label do not have network level identifier. It is the
> >egress router that created label for the FEC and when that label arrives
> at
> >the Egress LSR it knows that this label belongs to which FEC.
> >
> >My question here is packets are classified at the ingress router and they
> >been allocated to a FEC. How do Egress LSR has communicated to Ingress
> >router that which label to choose for which FEC.
> >
> >May be I misunderstood, then what is correct and how Egress router know
> >that what is the payload of MPLS packet.
> >
> >I am not talking about MPLS VPN here, but the simple MPLS.
> >
> >
> >
> >--
> >Thanks&regards
> >
> >Vishal
> >+91 8587900305
> >
> >Best way to predict the future ..... is to create it
> >
> >
> >Blogs and organic groups at http://www.ccie.net
> >
> >_______________________________________________________________________
> >Subscription information may be found at:
> >http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
>
>
>
>
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Are you a CCNP or CCIE and looking for a job? Check out 
www.PlatinumPlacement.com

http://onlinestudylist.com/mailman/listinfo/ccie_rs

Reply via email to