Chapter7.Multicast Routing and Switching

Chapter 7. Multicast Routing and Switching

The growing level of multimedia content available on corporate networks and the Internet has increased many organizations bandwidth requirements. Streaming video and audio applications are becoming more commonplace, with many of these audio/video streams originating from a single source and being sent to many receivers. For example, a video server may transmit a single video feed to thousands of receivers, which raises concerns about bandwidth usage and CPU overheads. The video server could send a video feed to each individual receiver, but doing so means the server has to generate thousands of video streams. So many streams would most likely saturate the link connected to the server and render the server useless due to the high CPU load incurred. Multicasting allows a one-to-many transmission that consists of a single data stream that is propagated to any host that wants to receive the data stream, without unnecessarily sending that data stream to hosts that do not want to receive the data stream. That means multicast traffic must be controlled in some fashion at both a Layer 2 level and Layer 3 level.

This chapter focuses on controlling multicast traffic in both Layer 2 and Layer 3 networks. After some initial introductory material, this chapter presents the following configuration scenarios, which provide you with the practical knowledge required to implement multicast traffic control on Layer 2 and Layer 3 networks:

• Scenario 7-1: Configuring PIM Dense Mode Multicast Routing

• Scenario 7-2: Configuring PIM Sparse Mode and PIM Sparse-Dense Mode Multicast Routing

• Scenario 7-3: Multicast Traffic Control on the LAN

• Scenario 7-4: Configuring IGMP Snooping

• Scenario 7-5: Configuring Cisco Group Management Protocol (CGMP)