Hi all,
I need some clarification about the following point. Let's consider a Bidirectional PIM deployment and, more specifically, a shared tree branch without receivers, that is a branch to which only multicast sources are attached. Will there be (*,G) state in the routers forming this branch? And, if yes, how is it formed, considering that no PIM Join is tranmitted through such routers?
I have looked up RC 5015 and it states:
"Source-only branches of the distribution tree for a group G are branches that do not lead to any receivers, but that are used to forward packets traveling upstream from sources towards the RPL. Routers along source-only branches only have the RPF interface to the RPA in their olist for G, and hence do not need to maintain any group specific state. Upstream forwarding can be performed using only RPA specific state. An implementation may decide to maintain group state for source-only branches for accounting or performance reasons. However, doing so requires data-driven events (to discover the groups with active sources), thus sacrificing one of the main benefits of BIDIR-PIM."
While in Cisco documentation about Bidir PIM I have found that "If a router is located on a sender-only branch, it will also create (*, G) state, but the olist will not include any interfaces"
I'm bit confused...Could someone help me out please?