A company’s HP Provision ASIC switches are configured to use PIM-SM mode to provide
multicast services. When an HP Provision ASIC switch receives a multicast stream, it determines
that the best path to the multicast source is not through the Rendezvous Point (RP). Which action
might this switch take?

A.
The switch may use the backup RP if this RP is in the path between the multicast source and
its receivers.

B.
The switch may send a graft message on the interface through which it reaches the multicast
source.

C.
The switch may establish itself as the new RP for the shortest path tree.

D.
The switch may decide to join the shortest path tree.

Explanation:
Shortest-Path Tree Operation. In the default PIM-SM configuration, after
an edge router receives the first packet of traffic for a multicast group
requested by a multicast receiver on that router, it uses Reverse Path Forwarding (RPF) to learn
the shortest path to the group source. The edge router then
stops using the RPT (Rendezvous-Point Tree) and begins using the shortest path tree (SPT)
connecting
the multicast source and the multicast receiver. In this case, when the edge
router begins receiving group traffic from the multicast source through the
SPT, it sends a prune message to the RP tree to terminate sending the
requested group traffic on that route.
When completed, the switchover from the RPT to a shorter SPT
can reduce unnecessary traffic concentrations in the network and reduce
multicast traffic throughput delays.