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ospf3 area-range metrics question

  • 1.  ospf3 area-range metrics question

    Posted 12-01-2020 15:09
    I have the following topology
    root@vMX2# run show route 10.100.0.0

    inet.0: 11 destinations, 11 routes (11 active, 0 holddown, 0 hidden)
    + = Active Route, - = Last Active, * = Both

    10.100.0.0/16 *[OSPF3/10] 00:05:34, metric 16777215
         Discard

    Any documentation explains this huge metrics ?

    thanks !!


  • 2.  RE: ospf3 area-range metrics question

    Posted 12-01-2020 19:02
    Hi gongyayu,

    16777215 is LSInfinity value that is used to mark prefix as unreachable by setting it's 24-bit metric field to all ones (for Summary and External LSAs, RFC3137)

    I think the route shown in your output is Summary route as below there is Discard action for it.  ABR (in your case vMX2) sends Summary LSA flagged as unreachable by setting it's 24-bit metric field to all ones when prefix is associated with the failed link and requests flush this prefix from receiver's LSDB by setting it's LSAge to MaxAge (3600 seconds).

    ------------------------------
    Regards,
    Elchin
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  • 3.  RE: ospf3 area-range metrics question

    Posted 12-01-2020 19:11
    thanks so much !!