Configuring Igmp Snooping Querier - H3C s3100-52P Operation Manual

Operation Manual – Multicast
H3C S3100-52P Ethernet Switch
Limit the number of
multicast groups on a port
Note:
To prevent bursting traffic in the network or performance deterioration of the device
caused by excessive multicast groups, you can set the maximum number of
multicast groups that the switch should process.
When the number of multicast groups exceeds the configured limit, the switch
removes its multicast forwarding entries starting from the oldest one. In this case,
the multicast packets for the removed multicast group(s) will be flooded in the VLAN
as unknown multicast packets. As a result, non-member ports can receive multicast
packets within a period of time. To avoid this from happening, enable the function of
dropping unknown multicast packets.

3.2.7 Configuring IGMP Snooping Querier

In an IP multicast network running IGMP, a multicast router is responsible for sending
IGMP general queries, so that all Layer 3 multicast devices can establish and maintain
multicast forwarding entries, thus to forward multicast traffic correctly at the network
layer. This router or Layer 3 switch is called IGMP querier.
However, a Layer 2 multicast switch does not support IGMP, and therefore cannot send
general queries by default. By enabling IGMP Snooping querier on a Layer 2 switch in a
VLAN where multicast traffic needs to be Layer-2 switched only and no multicast
routers are present, the Layer 2 switch will act as a querier to send IGMP general
queries, thus allowing multicast forwarding entries to be established and maintained at
the data link layer.
You can also configure the source address and interval of general queries to be sent
from the IGMP Snooping querier.
Follow these steps to configure IGMP Snooping querier:
Enter system view
Enable IGMP Snooping
Enter VLAN view
To do...
igmp-snooping group-limit
limit [ vlan vlan-list
[ overflow-replace ] ]
To do...
system-view
igmp-snooping enable
vlan vlan-id
Chapter 3 IGMP Snooping Configuration
Use the command...
Use the command...
3-11
Remarks
Required
The maximum number of
multicast groups on a port
is 256 by default.
Remarks
—
Required
By default, IGMP
Snooping is disabled.
—