Which of the following is a communication protocol that multicasts messages and information
among all member devices in an IP multicast group?

A.
ICMP

B.
IGMP

C.
BGP

D.
EGP

Explanation:

Internet Group Management Protocol (IGMP) is a communication protocol that multicasts
messages and information among all member devices in an IP multicast group. However,
multicast traffic is sent to a single MAC address but is processed by multiple hosts. It can be
effectively used for gaming and showing online videos. IGMP is vulnerable to network attacks.
Answer option A is incorrect. Internet Control Message Protocol (ICMP) is a maintenance protocol
that allows routers and host computers to swap basic control information when data is sent from
one computer to another. It is generally considered a part of the IP layer. It allows the computers
on a network to share error and status information. An ICMP message, which is encapsulated

within an IP datagram, is very useful to troubleshoot the network connectivity and can be routed
throughout the Internet.
Answer option C is incorrect. BGP stands for Border Gateway Protocol. It is an interautonomous
system routing protocol and is a form of Exterior Gateway Protocol (EGP). This protocol is defined
in RFC-1267 and RFC-1268. It is used for exchanging network reachability information with other
BGP systems. This information includes a complete list of intermediate autonomous systems that
the network traffic has to cover in order to reach a particular network. This information is used for
figuring out loop-free interdomain routing between autonomous systems. BGP-4 is the latest
version of BGP.
Answer option D is incorrect. Exterior Gateway Protocol (EGP) is a protocol that exchanges
routing information between different autonomous systems. It is commonly used between hosts on
the Internet to exchange routing table information. Border Gateway Protocol (BGP) is the only
active EGP.