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
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Configuring multicast routing and forwarding
Overview
The following tables are involved in multicast routing and forwarding:
• Multicast routing table of each multicast routing protocol, such as the PIM routing table.
• General multicast routing table that summarizes multicast routing information of different multicast
routing protocols. The multicast routing information from multicast sources to multicast groups are
stored in a set of (S, G) routing entries.
• Multicast forwarding table that guides multicast forwarding. The optimal routing entries in the
multicast routing table are added to the multicast forwarding table.
The term "interface" in the multicast routing and forwarding features collectively refers to Layer 3
interfaces, including VLAN interfaces and Layer 3 Ethernet interfaces. You can set an Ethernet port as a
Layer 3 interface by using the port link-mode route command (see Layer 2—LAN Switching
Configuration Guide).
RPF check mechanism
A multicast routing protocol uses Reverse path forwarding (RPF) check to ensure the multicast data
delivery along the correct paths when the multicast routing protocol creates multicast routing entries
based on the existing unicast routes or static multicast routes. RPF check also helps avoid data loops.
A multicast routing protocol uses the following tables to perform an RPF check:
• Unicast routing table—Contains unicast routing information.
• Static multicast routing table—Contains RPF routes that are manually configured.
Static multicast routing table is used for RPF check rather than multicast routing.
RPF check process
When performing an RPF check, the router searches its unicast routing table and static multicast routing
table at the same time using the following process:
1. The router separately chooses an optimal route from the unicast routing table and the static
multicast routing table:
{ The router looks up its unicast routing table by using the IP address of the packet source as the
destination address, and automatically chooses an optimal unicast route. The outgoing
interface of the route is the RPF interface and the next hop is the RPF neighbor. The router
considers the path of the packet that the RPF interface receives from the RPF neighbor as the
shortest path that leads back to the source.