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Shall I need to enable "auto-targeted-session" on protocol ldp ?

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  • 1.  Shall I need to enable "auto-targeted-session" on protocol ldp ?

    Posted 08-13-2020 01:15
      |   view attached

    Hi,

     

    I've enabled LDP/MPLS/RSVP on our backbone. The LSP is working by LDP with RSVP(BypassLSP).

    Just like this route: 

       192.168.146.9/32 *[LDP/9] 5d 16:19:47, metric 1
       > to 192.168.146.46 via ae0.0
       to 192.168.146.38 via ae8.1, label-switched-path ae0.0:BypassLSP->192.168.146.9
       [IS-IS/18] 13w6d 00:51:04, metric 1

     

    But I don't get if we need to enable this function "auto-targeted-session" on protocol LDP.

    This function looks like for LDP LFA. Should I need it ?

     

    BTW, I attached my configuration of one router about LDP/MPL/RSVP/IS-IS.

     

    Thanks

    Cloud


    #ldp
    #rsvp

    Attachment(s)

    rtf
    Configuration.rtf   2K 1 version


  • 2.  RE: Shall I need to enable "auto-targeted-session" on protocol ldp ?
    Best Answer

    Posted 08-13-2020 02:49

    Hello,

     


    @Cloud wrote:

    But I don't get if we need to enable this function "auto-targeted-session" on protocol LDP.

    This function looks like for LDP LFA. Should I need it ?

     

     

     

    The "auto-targeted-session" knob is for Remote LFA, it is not required for basic LFA.

    The difference is explained in the "MPLS in the SDN era" book on pages 696-703 and further on.

    Also please see RFC 5286 for basic LFA  https://tools.ietf.org/html/rfc5286 and RFC 7490 https://tools.ietf.org/html/rfc7490  for RLFA.

    You are running RLFA if You have "backup-spf-options remote-backup-calculation" knob enabled under OSPF or ISIS.

    If You don't have the "remote-backup-calculation" knob then You don't need "auto-targeted-session" knob.

    HTH

    Thx

    Alex