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  • 1.  (MPLS-TE) CSPF - Path Selection

    Posted 03-12-2014 03:58

    Hello,

     

    I have a question regarding CSPF path selection. According to the following link http://www.juniper.net/techpubs/en_US/junos10.4/topics/concept/mpls-cspf-path-selection-method.html

    in step 6 it states that if several paths have equal cost, the one whose last-hop address is the same as the LSP's destination will be chosen.

     

    This statement baffles me. Doesn't CSPF calculate a path to the egress LSR (taking into consideration all contraints)? Isn't always the egress LSR the last-hop address defined on the ingress LSR as follows?:

     

    [edit protocols mpls]

    mpls {

       label-switched-path path

          to egress LSR

       }

    }

     

    Many thanks in advance,

    George


    #MPLS
    #rsvp
    #cspf


  • 2.  RE: (MPLS-TE) CSPF - Path Selection
    Best Answer

     
    Posted 03-13-2014 05:26

    Well, assume egress router address configured ("to eggress LSR")  is not a loopback address but address assigned to interface X on egress router - then  if the  paths cost is the same, CSPF prefers the path which last hop address is matching IFL X address than the path that is terminating from other interface on the egress router.

     

     

    Best Regards,

    Krasimir Avramski



  • 3.  RE: (MPLS-TE) CSPF - Path Selection

    Posted 03-14-2014 03:54

    I see now Krasimir ! Thank you very much for your reply !

     

    Many thanks and best wishes,

    George