Multicast Routing

Chapter 5 introduced the concept of multicast transmission, where a multicast sender could send traffic destined for a Class D IP address, known as a multicast group, and devices on a network wanting to receive that transmission could join that multicast group. Let us now consider how a client joins a multicast group and how routers route multicast traffic. Keep in mind that one of the main goals with multicast traffic is to send that traffic only to devices in a network wanting to receive that traffic. Two primary protocols used for multicast are Internet Group Management Protocol (IGMP) and Protocol Independent Multicast (PIM).