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  • Content created by Rene Molenaar (CCIE #41726)

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Forum Replies

  1. Hi Rene,

    I setup up lab for 4 routers to allow one router and block other router, it’s not working, but for two routers like your lab its working.


    in this LAB I want to filter R1 as source to R4 which is configured group address 239.9.9…9, but its allowing all sources.


    interface GigabitEthernet1/0
     ip address
     ip pim sparse-mode
     negotiation auto
    ip pim rp-add


    interface GigabitEthernet1/0
     ip addre
    ... Continue reading in our forum

  2. Hi Rene,

    I setup same LAB in VIRL, the previous LAB was GNS3, right now its showing this debug message

    Aug 22 05:13:25.023: %PIM-4-INVALID_SRC_REG: Received Register from for (,, not willing to be RP

    from R2 (Which is the RP), but even though I’m receiing INVALID-Source address its still allowing to ping the group address and even setting up in multicast routing.

    (,, 00:02:26/00:00:33, flags: FT
     Incoming interface: GigabitEthernet0/1, RPF nbr
      Outgoing interface list:
        GigabitEthernet0/2, Forw
    ... Continue reading in our forum

  3. Hi Rene

    I changed topology this way its working without Issue


    Why its accepting R1 as source and not accepting Source Router as Source ?

    the difference between the Source router and R1 is that the Source router isn’t running any PIM mode, I just enabled ip multicast-routing. (and sure I modified the Access-list)

    is this means that if the DR it self generates multicast traffic as source, the Pim Accept Register will not effect it?.


  4. Hi Jama,

    It’s probably because the pings are sent from the G1/0 interface on the R1 router. When R2 doesn’t accept as a source, it sends a prune message to R1 so that it doesn’t forward this multicast traffic anymore. R1 however, is sourcing the traffic from its G1/0 interface so it’s not “multicast routed”.

    If you source the multicast traffic from a loopback interface on R1 that isn’t permitted on the access-list of R2, you’ll see that R1 no longer forwards it on its G1/0 interface because of the pruning.


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