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PIM-SM Assert vs DR

Hi all,

suppose to have a LAn with 3 routers. One capture the igmp joins and other two see the RP and the source with equalcost IGP.

Then the receive could receive 2 duplicated streams.

If I set the interface priority to fix the PIM-DR election on a LAN to one preferred node.

Is the DR also the winner of the Assert process?

I mean, shall I receive only one stream only from this node?

Thanks

G-.

1 REPLY

Re: PIM-SM Assert vs DR

Hello,

about assert messages:

If a router receives a multicast packet via an interface in the outgoing interface list associated with a

multicast source, send a PIM Assert message out the interface to resolve which router will continue

forwarding this traffic.

When the Assert mechanism is triggered on an interface, a PIM router sends a PIM Assert message

containing its metric to the source. All PIM routers on the network examine the metric in the PIM Assert

message to determine which router has the best metric back to the multicast source. The router with the best metric continues to forward traffic from this source onto the network while all other PIM routers prune their interface. If there is a tie in the metrics, the router addresses are used as the tiebreaker and the highest IP address wins.

And about DRs:

The DR is primarily used in sparse mode networks and has little meaning in dense mode networks.

The only exception to this rule is when IGMPv1 is in use on an interface. In this case, the PIM-DR also

functions as the IGMP Query Router since IGMPv1 does not have a Query Router election mechanism.

so, I dont think one thing is related to the other.

HTH,

if it does, please rate this post.

Vlad

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