Subject: Detection of MPLS

From: [email-masked]
Date: Wed, 10 Nov 1999 09:47:23 +0530

Hi,

   How does one detect that a packet is tagged or not?

   Let us say there is a set routers some of them are MPLS enabled and some are
   not....
        Consider a path formed by IP routing tables for a particular
destination,

     R1 --> R2 --> R3 --> R4 ---> R5 --> R6 --> R7

       Now say R4 is not MPLS enabled rest all are. Say there is downstream on
demand allocation of Labels. Now       how does LDP detect that whether to ask
next hop router for label allocation or not.

Thanks,
Ravi.

---

From: Anup Anil Cheruvathoor <[email-masked]>
Date: Mon, 15 Nov 1999 09:51:35 +0530

hi,
    In LDP the discovery of the link peers is done through an Hello protocol. The
hellos are
    send on multicast address.
    The routers on an interface which are MPLS enabled ( also having LDP ) would
reply back with an
    hello  message. Thus peers discover each other. Through this process an
adjacency is formed.

    Adjacency is used to create a session between peers for label distribution.

    A Router would request another Router for label allocation only if a session
was established between
    peers.

    For more information look at
    draft-ietf-mpls-ldp-06.txt.

regardx
-Anup

--

Name : Anup Anil Chervathoor
E-mail : mailto:[email-masked]
Web : www.ficon-tech.com