H3C Technologies H3C SecPath F1000-E - Manual (Page 618)

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NOTE:
•
Each device can have only one interface serving as the proxy interface.
• You cannot enable IGMP on an interface with IGMP proxying enabled. Moreover, only the igmp
require-router-alert, igmp send-router-alert, and igmp version commands can take effect on such an
interface.
• You cannot enable other multicast routing protocols (such as PIM-DM or PIM-SM) on an interface 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.
Configuring multicast forwarding on a downstream interface
Only queriers can forward multicast traffic but 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 must
enable multicast forwarding on this interface.
To enable multicast forwarding on a downstream interface
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Enable multicast forwarding on a
non-querier downstream interface. igmp proxying forwarding
Disabled by default
CAUTION:
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 might be
received on the multi-access network.
Displaying and maintaining IGMP
Task Command Remarks
Display IGMP group information.
display igmp group [ group-address |
interface interface-type
interface-number ] [ static | verbose ]
[ | { begin | exclude | include }
regular-expression ]
Available in any view