H3C Technologies H3C S7500E Series Switches - Manual (Page 127)

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Configuring IGMP Proxying
Configuration Prerequisites
Before configuring the IGMP proxying feature, complete the following tasks:
z Configure any unicast routing protocol so that all devices in the domain are interoperable at
the network layer.
z Enable IP multicast routing.
Enabling IGMP Proxying
You can enable IGMP proxying on the interface in the direction toward the root of the multicast
forwarding tree to make the device serve as an IGMP proxy.
Follow these steps to enable IGMP proxying:
To do… Use the command… Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Enable the IGMP proxying
feature
igmp proxying enable
Required
Disabled by default.
z Each device can have only one interface serving as the proxy interface. In scenarios with
multiple instances, IGMP proxying is configured on only one interface per instance.
z You cannot enable IGMP on interfaces with IGMP proxying enabled. Moreover, only the
igmp require-router-alert, igmp send-router-alert, and igmp version commands can
take effect on such interfaces.
z You cannot enable other multicast routing protocols (such as PIM-DM or PIM-SM) on
interfaces with IGMP proxying enabled, or vice versa. However, the source-lifetime,
source-policy, and ssm-policy commands configured in PIM view can still take effect. In
addition, in IGMPv1, the designated router (DR) is elected by the working multicast routing
protocol (such as PIM) to serve as the IGMP querier. Therefore, a downstream interface
running IGMPv1 cannot be elected as the DR and thus cannot serve as the IGMP querier.
z You cannot enable IGMP proxying on a VLAN interface with IGMP snooping enabled, or
vice versa.
Configuring Multicast Forwarding on a Downstream Interface
Typically, only queriers are able to forward multicast traffic while non-queriers have no multicast
forwarding capabilities, to avoid duplicate multicast flows. It is the same on IGMP proxy devices.