Which two commands are required to enable multicast on a router, knowing that the receivers only support IGMPv2? (Choose two.)
A. ip pim rp-address
B. ip pim ssm
C. ip pim sparse-mode
D. ip pim passive
The correct answer should be A, D.
B says SSM(Source Specific Multicast), which requires receivers to be in IGMP version 3. Question says the multicast receiver only supports IGMP version 2.
SSM implements the multicast with a shortest path, when the multicast source is limited and already known. Also in SSM, Rendezvous Point is not required to implement. It could be a hint to choose the right answer.
The ip pim passive in D is a command for Multicast Stub Routing.
When the multicast receivers aren’t connected with enough bandwidth or narrow circuits, sometimes we do not want multicast Flood / Prune to use the bandwidth. Using a Multicast Stub Routing may be useful in the situation.