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Forum Replies

  1. Hello Hussien

    Which router will be chosen depends on what is called the PIM Assert mechanism. You can find detailed information about this at the following lesson:


    ... Continue reading in our forum

  2. Hi Hussien,

    It’s the job of the DR (Designated Router) to forward the PIM join upstream.


  3. Hi Hussein,

    In my example, R4 was only a receiver so it didn’t participate in PIM, which makes R2 or R3 the designated router. When you enable PIM on R4 and it is a DR, it will have two equal unicast routes to so it has to make a choice.

    RPF does not use both routes but uses the PIM neighbor with the highest IP address to go upstream.

    Let’s look at an example. I’ll turn R4 into a PIM router by enabling it on the FastEthernet0/0 interface. I’ll also create a loopback that will have IGMP join on it so that R4 is the DR for the loopback segment:

    ... Continue reading in our forum

  4. Its seems relatively straightforward when explained. However, may become less so when starting to apply in real world :slight_smile: . One real world example - client is facing redundant pair of routers with HSRP. Will both routers still participate in DR election? How its going to work then if router with lower IP is the active router? Looks like the joins may not be sent as DR (being passive) will not receive client request and active router will receive it but will not send join to RP, since its not a DR. If thats the case does it mean in HSRP case (which is very often)

    ... Continue reading in our forum

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