Refer to the Exhibit.
In the exhibit, what happens if the source starts sending multicast traffic toward R1 and there are
receivers registered at the RP?
A.
R1 encapsulates the multicast packets into a PIM register multicast packet.
B.
R1 encapsulates the multicast packets into PIM join unicast messages.
C.
R1 forwards the multicast packets on the S,G tree towards the RP.
D.
R1 tunnels the multicast packets in PIM register messages toward the RP.
Explanation:
i think the answer is A
“When a source becomes active, the source DR encapsulates multicast data packets into a PIM register message and sends them by means of unicast to the RP router”.
http://www.juniper.net/documentation/en_US/junos14.2/topics/topic-map/mcast-pim-sparse-mode.html
There is no difference between “tunnels the multicast packets in” and “encapsulates the multicast packets into” as tunnel is achieved using encapsulating a packet, both are correct.
A is not correct because it is a unicast packet and not a multicast packet. There is no such thing as a pim register multicast packet
the register message is an unicast message not a multicast so option D is the correct.