Configuring Multicast Forwarding On A Downstream Interface - H3C LS-3100-52P-OVS-H3 Operation Manual

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.
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.
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.
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. Only
the downstream interfaces acting as a querier can forward multicast traffic to downstream hosts.
However, when a downstream interface of a proxy device fails to win the querier election, you need to
enable multicast forwarding on this interface.
Follow these steps to enable multicast forwarding on a downstream interface
To do...
Enter system view
Enter interface view
Enable multicast forwarding on a
non-querier downstream interface
On a multi-access network with more than one IGMP proxy device, you cannot enable multicast
forwarding on any other non-querier downstream interface after one of the downstream interfaces of
these IGMP proxy devices has been elected as the querier. Otherwise, duplicate multicast flows may be
received on the multi-access network.
Use the command...
system-view
interface interface-type
interface-number
igmp proxying forwarding
1-18
Remarks
—
—
Required
Disabled by default.