Configuring Igmp Snooping Querier - 3Com E4500-24 Cli Configuration Manual

Configuring IGMP Snooping Querier

In an IP multicast network running IGMP, one dedicated multicast device is responsible for sending
IGMP general queries, and this router or Layer 3 switch is called the 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.
Upon receiving an IGMP query with the source IP address 0.0.0.0 on a port, the switch does not enlist
that port as a dynamic router port. This may prevent multicast forwarding entries from being correctly
created at the data link layer and cause multicast traffic forwarding failure in the end. When a Layer 2
device acts as an IGMP-Snooping querier, to avoid the aforesaid problem, configure a non-all-zero IP
address as the source IP address of IGMP queries.
IGMP Snooping querier related configurations include:
Enabling IGMP Snooping querier,
Configuring the IGMP query interval, and
Configuring the source address to be carried in IGMP general and group specific queries.
Enabling IGMP Snooping querier
Follow these steps to enable IGMP Snooping querier:
To do...
Enter system view
Enable IGMP Snooping
Enter VLAN view
Enable IGMP Snooping
Enable IGMP Snooping querier
Configuring IGMP query interval
Follow these steps to configure IGMP query interval:
To do...
Enter system view
Enter VLAN view
Configure the IGMP query
interval
Use the command...
system-view
igmp-snooping enable
vlan vlan-id
igmp-snooping enable
igmp-snooping querier
Use the command...
system-view
vlan vlan-id
igmp-snooping
query-interval seconds
1-10
Remarks
—
Required
By default, IGMP Snooping is
disabled.
—
Required
By default, IGMP Snooping is
disabled.
Required
By default, IGMP Snooping
querier is disabled.
Remarks
—
—
Optional
60 seconds by default.