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An IGMP proxy device performs host functions on the upstream interface based on the database. It
responds to queries according to the information in the database or sends join/leave messages when the
database changes. On the other hand, the IGMP proxy device performs router functions on the
downstream interfaces by participating in the querier election, sending queries, and maintaining
memberships based on the reports.
IGMP support for VPNs
IGMP maintains group memberships on a per-interface base. After receiving an IGMP message on an
interface, IGMP processes the packet within the VPN that the interface belongs to. If IGMP that runs in a
VPN needs to exchange information with another multicast protocol, it passes the information only to the
protocol that runs in this VPN.
Protocols and standards
•
RFC 1112,
Host Extensions for IP Multicasting
•
RFC 2236,
Internet Group Management Protocol, Version 2
•
RFC 3376,
Internet Group Management Protocol, Version 3
•
RFC 4605,
Internet Group Management Protocol (IGMP)/Multicast Listener Discovery (MLD)-Based
Multicast Forwarding ("IGMP/MLD Proxying")
IGMP configuration task list
For the configuration tasks in this section, the following rules apply:
•
The configurations made in IGMP view are effective on all interfaces. The configurations made in
interface view are effective only on the current interface.
•
A configuration made in interface view always has priority over the same global configuration in
IGMP view. If you do not make the configuration in interface view, the corresponding global
configuration made in IGMP view applies to the interface.
Complete these tasks to configure IGMP:
Task
Remarks
Configuring basic IGMP
functions
Required.
Optional.
Configuring an interface as a static member interface
Optional.
Configuring a multicast group filter
Optional.
Setting the maximum number of multicast groups that an
Optional.
Configuring Router-Alert option handling methods
Optional.
Configuring IGMP query and response parameters
Optional.
Enabling IGMP fast-leave processing
Optional.
Enabling the IGMP host tracking function
Optional.
Optional.
Optional.