16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series
Configuration Tasks
103
Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ
To disable IGMP snooping on a VLAN interface, use the no ip igmp snooping vlan vlan-id global
configuration command for the specified VLAN number (for example, vlan1).
Enabling IGMP Immediate-Leave Processing
When you enable IGMP Immediate-Leave processing, the Ethernet switch network module immediately
removes a port from the IP multicast group when it detects an IGMP version 2 leave message on that
port. Immediate-Leave processing allows the switch to remove an interface that sends a leave message
from the forwarding table without first sending out group-specific queries to the interface. You should
use the Immediate-Leave feature only when there is only a single receiver present on every port in the
VLAN.
Beginning in privileged EXEC mode, follow these steps to enable IGMP Immediate-Leave processing:
To disable Immediate-Leave processing, follow Steps 1 and 2 to enter interface configuration mode, and
use the no ip igmp snooping vlan vlan-id immediate-leave global configuration command.
Statically Configuring an Interface to Join a Group
Ports normally join multicast groups through the IGMP report message, but you can also statically
configure a host on an interface.
Beginning in privileged EXEC mode, follow these steps to add a port as a member of a multicast group:
Step 4
show ip igmp snooping [vlan vlan-id] Displays snooping configuration.
(Optional) vlan-id is the number of the VLAN.
Step 5
copy running-config startup-config
(Optional) Saves your configuration to the startup configuration.
Command
Purpose
Command
Purpose
Step 1
configure terminal
Enters global configuration mode.
Step 2
ip igmp snooping vlan vlan-id
immediate-leave
Enables IGMP Immediate-Leave processing on the VLAN interface.
Step 3
end
Returns to privileged EXEC mode.
Command
Purpose
Step 1
configure terminal
Enters global configuration mode
Step 2
ip igmp snooping vlan vlan-id static
mac-address interface interface-id
Statically configures a port as a member of a multicast group:
•
vlan-id is the multicast group VLAN ID.
•
mac-address is the group MAC address.
•
interface-id is the member port.
Step 3
end
Returns to privileged EXEC mode.