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

    Posted 03-12-2014 03:58



    I have a question regarding CSPF path selection. According to the following link

    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,



  • 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,