Which of the following protocols is used for router multicas

Which of the following protocols is used for router multicasting?

A. ICMP

B. RIPv1

C. 224.0.0.1

D. IGMP

Solution

D. Internet Group Management Protocol (IGMP) is used by hosts to report multicast group memberships to neighboring multicast routers. Security problems exist with IGMP because anyone can start a multicast group or join an existing one. Answer A is incorrect because ICMP is used for logical errors and diagnostics. Answer B is incorrect because the Routing Information Protocol (RIP) is a broadcast-based routing protocol. Answer C is incorrect because although 224.0.0.1 is a multicast address, it is not a protocol used for multicast management.