Cisco Systems 2940 Switch User Manual


 
16-10
Catalyst 2940 Switch Software Configuration Guide
78-15507-02
Chapter 16 Configuring IGMP Snooping and MVR
Configuring IGMP Snooping
This example shows how to statically configure a host on an interface and verify the configuration:
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 1 static 0100.5e00.0203 interface gigabitethernet0/1
Switch(config)# end
Switch# show mac address-table multicast vlan 1
Vlan Mac Address Type Ports
---- ----------- ---- -----
1 0100.5e00.0203 USER Gi0/1
Enabling IGMP Immediate-Leave Processing
When you enable IGMP Immediate-Leave processing, the switch immediately removes a port when it
detects an IGMP version 2 leave message on that port. You should use the Immediate-Leave feature only
when there is a single receiver present on every port in the VLAN.
Immediate Leave is supported with only IGMP version 2 hosts.
Beginning in privileged EXEC mode, follow these steps to enable IGMP Immediate-Leave processing:
To disable IGMP Immediate-Leave on a VLAN, use the no ip igmp snooping vlan vlan-id
immediate-leave global configuration command.
This example shows how to enable IGMP immediate-leave processing on VLAN 130:
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 130 immediate-leave
Switch(config)# end
Disabling IGMP Report Suppression
IGMP report suppression is enabled by default. When it is enabled, the switch forwards only one IGMP
report per multicast router query. When report suppression is disabled, all IGMP reports are forwarded
to the multicast routers.
Note IGMP report suppression is supported only when the multicast query has IGMPv1 and IGMPv2 reports.
This feature is not supported when the query includes IGMPv3 reports.
Command Purpose
Step 1
configure terminal Enter global configuration mode
Step 2
ip igmp snooping vlan vlan-id
immediate-leave
Enable IGMP Immediate-Leave processing on the VLAN interface.
Step 3
end Return to privileged EXEC mode.
Step 4
show ip igmp snooping vlan vlan-id Verify that Immediate Leave is enabled on the VLAN.
Step 5
copy running-config startup-config (Optional) Save your entries in the configuration file.