H3C Technologies H3C S10500 Series Switches - Manual (Page 130)

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Configuring multicast forwarding on a downstream interface
Only queriers can forward multicast traffic but non-queriers have no multicast forwarding capabilities.
This design helps avoid duplicate multicast flows. It is the same on IGMP proxy switches. Only the
downstream interfaces acting as a querier can forward multicast traffic to downstream hosts.
However, when a downstream interface of a proxy switch fails to win the querier election, you must
enable multicast forwarding on this interface.
Follow these steps to enable multicast forwarding on a downstream interface
To do… Use the command… Remarks
Enter system view system-view —
Enter interface view
interface interface-type
interface-number
—
Enable multicast forwarding on a
non-querier downstream interface
igmp proxying forwarding
Required
Disabled by default.
CAUTION:
On a multi-access network with more than one IGMP proxy switch, you cannot enable multicast
forwarding on any other non-querier downstream interface after one of the downstream interfaces of
these IGMP proxy switches has been elected as the querier. Otherwise, duplicate multicast flows might be
received on the multi-access network.
Displaying and maintaining IGMP
To do... Use the command...
Display IGMP group information
display igmp [ all-instance | vpn-instance
vpn-instance-name ] group [ group-address |
interface interface-type interface-number ] [ static |
verbose ] [ | { begin | exclude | include }
regular-expression ]
Available in any
view
Display the Layer 2 port
information of IGMP groups (in IRF
mode)
display igmp group port-info [ vlan vlan-id ]
[ chassis chassis-number slot slot-number ]
[ verbose ] [ | { begin | exclude | include }
regular-expression ]
Available in any
view
Display the Layer 2 port
information of IGMP groups (in
standalone mode)
display igmp group port-info [ vlan vlan-id ] [ slot
slot-number ] [ verbose ] [ | { begin | exclude |
include } regular-expression ]
Available in any
view
Display information about the hosts
tracked by IGMP on an interface
display igmp host interface interface-type
interface-number group group-address [ source
source-address ] [ | { begin | exclude | include }
regular-expression ]
Available in any
view
Display information about the hosts
tracked by IGMP on the Layer 2
ports (in standalone mode)
display igmp host port-info vlan vlan-id group
group-address [ source source-address ] [ vlan
vlan-id ] [ slot slot-number ] [ | { begin | exclude |
include } regular-expression ]
Available in any
view