Chapter 9. Implementing Multicast on Catalyst Switches

This chapter covers the following topics:

  • Understanding IGMPv1 and IGMPv2

  • Multicast flooding

  • IGMP snooping

  • CGMP

  • IGMP snooping versus CGMP

Multicast deployments have increased exponentially over the past 4 years. A single host sources traffic to a multicast group, which has multiple members associated with the group. Instead of forwarding unicast traffic to each host on the network, multicast allows the source to send the traffic once, and any host that joins that specific multicast group can receive the stream. As a result, multicast is a one-to-many model that helps reduce network traffic. This chapter will cover Internet Group Management Protocol (IGMP) snooping and Cisco Group Management Protocol (CGMP) in detail.