Multicast Routing Protocols
Glenn Warnock B.Sc., Mira Ghafary B.Sc., Ghassan Shaheen M.Sc. · 2015
This chapter describes the protocols used to build and maintain the multicast distribution trees (MDTs) that forward IP multicast data. It explains the operation of Internet Group Management Protocol (IGMP), Multicast Listener Discovery protocol (MLD), and Protocol Independent Multicast (PIM), and illustrates the step-by-step construction of the MDT. Configuration and verification of these protocols in SR OS (Alcatel-Lucent Service Router Operating System) are also covered. IGMP is the multicast signaling protocol used in IPv4 between a multicast receiver and its local router. Under normal circumstances, a multicast MAC address is never received as a source MAC address, so it is never learned by a switch nor added to the FDB. IGMPv3 introduces some changes to the base protocol operation and adds support for SSM. Any-source multicast (ASM) is implemented in IGMPv3 by using a Report message with an empty Exclude list.