User's Manual

Table Of Contents
317
Users Manual of CS-6306R
Chapter 30. IGMP-Snooping Configuration
IGMP-snooping Configuration 30.1
30.1.1 IGMP-snooping Configuration Task
The task of IGMP-snooping is to maintain the relationships between VLAN and group address and to update
simultaneously with the multicast changes, enabling layer-2 switches to forward data according to the
topology structure of the multicast group.
The main functions of IGMP-snooping are shown as follows:
Listening IGMP message;
Maintaining the relationship table between VLAN and group address;
Keeping the IGMP entity of host and the IGMP entity of router in the same state to prevent flooding from
occurring.
Because igmp-snooping realizes the above functions by listening the query
message and report message of igmp, igmp-snooping can function properly only
when it works on the multicast router, that is, the switch must periodically receive
the igmp query information from the router. The router age timer of igmp-
snooping
must be set to a time value that is bigger than the group query period of the
multicast router connecting igmp-snooping. You can check the multicast router
information in each VLAN by running show ip igmp-snooping.
Enabling/Disabling IGMP-snooping of VLAN
Adding/Deleting static multicast address of VLAN
Configuring immediate-leave of VLAN
Configuring the function to filter multicast message without registered destination address
Configuring the Router Age timer of IGMP-snooping
Configuring the Response Time timer of IGMP-snooping
Configuring IGMP Querier of IGMP-snooping
Monitoring and maintaining IGMP-snooping
IGMP-snooping configuration example
30.1.1.1 Enabling/Disabling IGMP-Snooping of VLAN
Perform the following configuration in global configuration mode:
Command Description
ip igmp-snooping [vlanvlan_id ]
Enables IGMP-snooping of VLAN.
no ip igmp-snooping [vlanvlan_id ]
Resumes the default configuration.
If vlan is not specified, all vlans in the system, including vlans created later, can be enabled or disabled.
In the default configuration, IGMP-snooping of all VLANs is enabled, just as the ip igmp-snooping command
is configured.