R21xx-HP FlexFabric 11900 IP Multicast Configuration Guide
Table Of Contents
- Title Page
- Contents
- Multicast overview
- Configuring IGMP snooping
- Overview
- IGMP snooping configuration task list
- Configuring basic IGMP snooping functions
- Configuring IGMP snooping port functions
- Configuring IGMP snooping policies
- Displaying and maintaining IGMP snooping
- IGMP snooping configuration examples
- Troubleshooting IGMP snooping
- Configuring multicast routing and forwarding
- Configuring IGMP
- Configuring PIM
- Overview
- Configuring PIM-DM
- Configuring PIM-SM
- Configuring common PIM features
- Displaying and maintaining PIM
- PIM configuration examples
- Troubleshooting PIM
- Configuring MLD snooping
- Overview
- MLD snooping configuration task list
- Configuring basic MLD snooping functions
- Configuring MLD snooping port functions
- Configuring MLD snooping policies
- Displaying and maintaining MLD snooping
- MLD snooping configuration examples
- Troubleshooting MLD snooping
- Configuring IPv6 multicast routing and forwarding
- Configuring MLD
- Configuring IPv6 PIM
- PIM overview
- Configuring IPv6 PIM-DM
- Configuring IPv6 PIM-SM
- Configuring common IPv6 PIM features
- Displaying and maintaining IPv6 PIM
- IPv6 PIM configuration examples
- Troubleshooting IPv6 PIM
- Support and other resources
- Index

4
• Routers or Layer 3 switches that support Layer 3 multicast are called "multicast routers" or "Layer 3
multicast devices." In addition to providing the multicast routing function, a multicast router can also
manage multicast group memberships on stub subnets with attached group members. A multicast
router itself can be a multicast group member.
For a better understanding of the multicast concept, you can compare multicast transmission to the
transmission of TV programs.
Table 1 Comparing TV program transmission and multicast transmission
TV program transmission Multicast transmission
A TV station transmits a TV program through a
channel.
A multicast source sends multicast data to a multicast
group.
A user tunes the TV set to the channel. A receiver joins the multicast group.
The user starts to watch the TV program transmitted
by the TV station on the channel.
The receiver starts to receive the multicast data that the
source is sending to the multicast group.
The user turns off the TV set or tunes to another
channel.
The receiver leaves the multicast group or joins another
group.
Common notations in multicast
The following notations are commonly used in multicast transmission:
• (*, G)—Rendezvous point tree (RPT), or a multicast packet that any multicast source sends to
multicast group G. The asterisk (*) represents any multicast source, and "G" represents a specific
multicast group.
• (S, G)—Shortest path tree (SPT), or a multicast packet that multicast source "S" sends to multicast
group "G." "S" represents a specific multicast source, and "G" represents a specific multicast
group.
For more information about the concepts RPT and SPT, see "Configuring PIM " and
"Configuring IPv6
PIM."
Multicast benefits and applications
Multicast benefits
• Enhanced efficiency—Reduces the processor load of information source servers and network
devices.
• Optimal performance—Reduces redundant traffic.
• Distributed application—Enables point-to-multipoint applications at the price of minimum network
resources.










