[c-nsp] Multicast clarification

[Martin Barry]

$quoted_author = "Arie Vayner (avayner)" ;
> 
> Without this functionality the routers would not be able to detect new
> sources as the switch would not replicate the stream, and we would never
> know about this source.

Understood.

But in our situation this VLAN is just a multicast traffic sink, it is not
retransmitted.

There are two routers because there are multiple sources of multicast
traffic.

 
> If both routers are talking PIM between them then only one of the them
> would be the DR (Designated Router), and only this router would be
> forwarding packets received on this LAN domain.

We are using PIM neighbour filtering to prevent the routers associating
because they are handling different multicast traffic.

This is why my question focused on the 3750 stack. It seems that it's
forwarding multicast out all mrouter ports except the ingress and I was
wondering if there is a way to prevent this as router B never needs to see
router A's multicast streams.

cheers
Marty